French Onion Soup

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French Onion Soup is our favorite soup. In this post I show you how to make a really flavorful french onion soup with two ways of broiling (grilling) and toasting bread in a pan.

french onion soup in two cream colored soup bowls with spoons on a black slate tray. soup garnished with some parsley.

About this recipe

I had got so many requests for this classic French soup. In fact, it is one of those recipes for which I have got maximum requests from our readers and fans.

French onion soup is made with caramelizing onions in butter which are then deglazed with dry white wine and further cooked with meat stock or veggie stock. Then finished with toasted bread or croutons with melted cheese.

I make this vegetarian version of the soup with a good homemade vegetable stock. Being an an essential ingredient the stock can make or break your soup. I suggest to use homemade stock or a low sodium stock.

The most important technique to get this dish right and bang on the flavors is caramelizing the onions. They have to be done perfectly and right.

The time that is taken to caramelize the onions will be about 40 to 45 minutes depending on the pan thickness and size. It took me an exact 44 minutes to caramelize the onions. So go slow and steady when sautéing the onions. Do not rush.

You have the option to broil (grill) or toast bread separately. Mostly, I place the toasted bread topped with cheese on the soup and broil in the oven till cheese melts. You can even bake cheese toasts separately and then place it on the soup while serving. I have shared both the methods below. Choose what is easy for you.

There are many variants of this soup though. I am sharing the recipe for a much-loved soup dish in my home after our favorites Tomato Soup and Sweet Corn Soup.

Ingredients you need

  • Onions: Any variety of onions can be added like red, yellow, white onions or shallots. Depending on the type of onions the flavors will vary. I prefer this soup with red onions. Just make sure to slice the onions evenly so that they get cooked uniformly.
  • Stock: Both meat-based stock and vegetable broth (veggie stock) work well. The stock has to be really good as apart from the caramelized flavor of the onions, a flavorful stock also makes the soup tasty. But I would suggest to make your own homemade stock and add in the soup. I have added a really flavorful vegetable stock (I will share the recipe soon).
  • Bread or croutons (croute): Either can be added. Both work well in the recipe. You can use a couple of days of leftover bread or even use a baguette or french bread.
  • Cheese: To get the authentic taste and flavor, I would definitely recommend using Gruyere cheese (vegetarian). If you do not have Gruyere cheese, then use Swiss cheese instead.
  • Herbs: The herbs that I add are bay leaf, rosemary and parsley. I prefer using fresh herbs but dried herbs can be subbed.

Vegan options

  1. Butter: Replace with a neutral-flavored oil or olive oil or vegan butter.
  2. Cheese: Substitute with vegan cheese.
  3. Stock: Use a stock made completely with vegetables.

french onion soup in two cream colored soup bowls with spoons on a black slate tray. soup garnished with some parsley.
Step-by-Step Guide

How to make French Onion Soup

Preparation
1. Peel, rinse and thinly slice 4 medium-sized onions (300 grams). You will need 3 cups of thinly sliced onions. Sometimes there are some black spots or marks on the onions and these need to be completely rinsed before slicing the onions. Finely chop or mince two small to medium-sized garlic cloves and keep aside.

sliced onions on a chopping board

Cooking onions
2. Take a heavy pan or pot. Place on the stovetop. Add 3 tablespoons butter and let the butter melt.

butter being melted in a pan

3. When the butter starts melting, add the sliced onions.

onions added to melted butter

4. Mix the onions with the butter really well.

onions mixed with the butter

5. Add a pinch of salt and stir.

a pinch of salt being added to the onions

6. Stirring often continue to sauté the onions on a low or medium-low flame.

onions being sautéed

7. First, the onions will become translucent. Continue to stir at intervals of 2 to 3 minutes.

onions have softened

8. After some minutes the onions will start to become light golden.

onions have turned light golden

9. The onions need to be cooked more till they reach the caramelized state. So stirring often sauté them till they become golden. After the onions reach a light golden stage, they have to be stirred continuously so that they are evenly cooked and browned.

onions have caramelized


Deglazing
10. When the onions have caramelized and have a nice golden color to them, add 2 tablespoons dry white wine. If you do not have white wine, then add ½ to 1 tablespoon apple cider vinegar or white wine vinegar or red wine vinegar or sherry.

dry white wine being added to the caramelized onions

11. Deglaze and scrape, remove all the stuck bits of browned onions from the bottom. Sauté for 1 to 2 minutes on a low to medium-low flame.

deglazing with dry white onion

Adding flour
12. Add 2 tablespoons whole wheat flour or all-purpose flour.

flour added to the onions

13. Mix very well and sauté for 2 minutes on a low to medium-low flame.

the onions are sauteed for 2 minutes after flour is added

14. Add ½ teaspoon finely chopped garlic and 1 bay leaf. Stir and sauté for a minute. If the onions start sticking to the pan, then sprinkle some water or stock.

garlic and bay leaf are added

15. Add 3.5 cups of vegetable stock.

vegetable stock is being added

16. Place 1 sprig of rosemary on the stock.

a sprig of rosemary placed on the stock

Cooking french onion soup

17. Season with salt as per taste. If the stock has salt in it, then you can skip adding salt or add less salt. The homemade vegetable stock which I had used did not have any salt.

after 30 minutes of simmering, seasoning with salt

18. Add ¼ to ½ teaspoon freshly crushed black pepper. Mix again.

seasoning with crushed black pepper

19. Cover the pan. Simmer onion soup for 30 minutes on a low flame. You can check the soup while it is simmering after an interval of 10 to 15 minutes.

pan covered with lid and soup being simmered for 30 minutes

20. In this below photo, the french onion soup is done and ready to be served.

french onion soup is done

Toasting Bread
21. When the soup is simmering, toast the slices of bread or baguette or french bread. Slice a french bread.

baguette being sliced

22. Place the bread slices on a baking tray. Brush with some melted butter or olive oil.

baguette slices brushed with olive oil and placed on baking tray

23. In a preheated oven toast the slices at 230 degrees Celsius or 450 degrees Fahrenheit. Preheat the oven for 15 minutes at the same temperature of 230 degrees celsius. Halfway through remove the tray and turn each slice.

baguette slices being toasted in the oven

24. Remove and keep aside when the slices become light golden or lightly toasted.

toasted baguette slices

Broiling (Grilling) 
25. Now you can use baking safe soup bowls for individual servings or use a baking safe pot or pan. Pour the soup in these bowls. If you have used a dutch oven for making the soup, then you can place the croutons or toasted bread slices directly in it.

individual serving bowls with soup in them

26. Place toasted bread slices on the onion soup.

toasted baguette slices being placed on the soup.

27. Sprinkle grated gruyere cheese (vegetarian) all over the toasted bread slices.

baguette slices topped with grated gruyere cheese

28. Place the bowls on a baking tray. Then keep in a preheated oven and broil at 230 degrees Celsius till the cheese melts. Broiling means keeping the pan or tray beneath the top heating element of the oven. The top heating element should be used when baking. The heat emanating from the top heating element melts the cheese. You can preheat the oven for 15 minutes.

soup bowls placed in the oven

29. Let cheese melt or become golden. 
Remove and serve hot. You can garnish with some chives or parsley while serving.

soup bowls removed from the oven with the cheese melted and golden


Baking Cheese toasts separately

30. For baking the cheese toasts separately
, sprinkle grated gruyere cheese (vegetarian) on the toasted bread slices.

toasted baguette slices with grated gruyere cheese on them

31. Bake at 230 degrees Celsius in a preheated oven till the cheese melts. Keep the tray near the top heating element so that the cheese melts quickly.

baguette slices in the oven

32. Bake till the cheese melts.

baguette slices with cheese melted on top

33. Pour steaming hot french onion soup in soup bowls. Place the cheese toasts on the onion soup. Garnish with some parsley or chives while serving.

french onion soup in a cream soup bowl with red handles with toasted baguette slices with melted cheese on top.

Serving Suggestions

Serve french onion soup as a starter to your meal. You can even have this soup as a light dinner meal.

Tips

Expert Tips

  • Herbs: You can skip adding herbs like rosemary or parsley in the recipe completely. Fresh thyme can also be added instead of rosemary.
  • Vegetable stock: Avoid using packaged stock having a high sodium content. It is better to make vegetable stock and use it in the recipe.
  • Flour: You can either whole wheat flour or all-purpose flour.
  • On caramelizing onions: For the soup to have a truly authentic and great flavor, it is important to caramelize the onions really well. So use a heavy pan or pot. Stir often when sautéing the onions. Toward the end stage when the onions become light golden, you have to stir often so that the onions get an even golden color and do not burn or darken. So stirring and cooking onions on a low to medium-low flame is the key. Even a slight burning of the onions will ruin the entire soup.
  • Wine: You can use sherry wine or dry white wine. You can even use red wine. If you do not plan to add wine, then use vinegar. I suggest ½ to 1 tablespoon of white wine vinegar, red wine vinegar or apple cider vinegar.
  • Gluten-free option: For the bread, use a gluten-free bread like a rice flour bread.
  • Cheese: Apart from Gruyere cheese, you can also add a vegetarian Parmesan cheese.

More Classic Soup Recipes

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french onion soup in two cream colored soup bowls with spoons on a black slate tray. soup garnished with some parsley.

French Onion Soup

Our favorite French Onion Soup made vegetarian with the classic recipe.
5 from 15 votes
Prep Time 5 minutes
Cook Time 1 hour 15 minutes
Total Time 1 hour 20 minutes
Cuisine French, World
Course Appetizers, Starters
Diet Vegetarian
Difficulty Level Moderate
Servings 3
Units

Ingredients

  • 3 cups thinly sliced onions or 300 grams (0.66 pounds) or 4 medium-sized onions
  • 3 tablespoons Butter – can use either salted or unsalted butter
  • 2 tablespoons dry white wine or ½ to 1 tablespoon apple cider vinegar
  • 2 tablespoons whole wheat flour or all-purpose flour
  • 1 bay leaf – tejpatta (indian bay leaf) can also be added
  • ½ teaspoon finely chopped garlic or 2 small to medium garlic cloves, finely chopped or minced
  • 3.5 cups Vegetable Stock – preferably a flavorful homemade stock
  • salt as required – optional
  • ¼ to ½ teaspoon freshly crushed black pepper
  • 1 sprig of rosemary or thyme – optional
  • ½ a loaf of french bread or baguette or sandwich bread
  • 6 tablespoons grated gruyere cheese (vegetarian) or add as required
  • few parsley or chives for garnish – optional

Instructions
 

Preparation

  • Peel, rinse and slice the onions thinly and evenly. Finely chop or mince two garlic cloves and keep aside.

Cooking onions

  • Place a heavy pan on the stovetop. Add butter.
  • When butter states melting, add the sliced onions with a pinch of salt.
  • Mix the onions with the butter really well.
  • Stirring often continue to sauté the onions on a low or medium-low flame till the onions caramelize.
  • Initially stir the onions after an interval of 2 to 3 minutes till they become light golden. When the onions turn light golden, then stir the onions continuously for even cooking and browning.

Deglazing

  • Once the onions have caramelized and have a nice golden color to them, add 2 tablespoons dry white wine.
  • Deglaze and remove all the stuck bits of caramelized onions from the bottom of the pan. Sauté for 1 to 2 minutes.

Adding flour

  • Now add flour.
 Mix very well and sauté for 2 minutes.
  • Then add the garlic and bay leaf. Mix well and sauté for a minute. If the onions start sticking to the pan, then sprinkle some water or stock.
  • Add the vegetable stock, 1 rosemary sprig. Also, season with salt and freshly crushed black pepper. stir and mix.
  • Salt is added as the veggie stock I had made, did not have any salt. If using stock with salt in it, then you can skip adding salt or add less of it.

Cooking soup

  • Cover the pan.
  • Simmer for 30 minutes on a low flame.
  • You can check the soup while it is simmering after an interval of 10 to 15 minutes. 

Toasting Bread or Baguette slices

  • When the soup is simmering, toast the slices of french bread or baguette or regular wheat bread or white bread. Slice the french bread.
  • Place the baguette slices on a baking tray. Brush with some melted butter or olive oil.
  • In a preheated oven toast bread slices at 230 degrees Celsius (450 degrees Fahrenheit) till light golden.

Broiling (Grilling)

  • Pour soup in a baking safe soup bowls for individual servings or use a baking safe pot or pan.
  • Place toasted bread slices on the onion soup.
  • Sprinkle grated gruyere cheese all over the toasted bread slices.
  • Place the bowls in a baking tray. Keep the tray in a preheated oven and broil at 230 degrees Celsius (450 degrees Fahrenheit) till the cheese melts. Broiling means keeping the pan or tray beneath the top heating element of the oven. The top heating element should be used when baking.
  • Let cheese melt or become golden. 
Remove and serve hot garnished with some parsley or chives.

Baking Cheese toasts separately

  • For baking the cheese toasts separately
 top grated gruyere cheese on the toasted baguette slices.
  • Bake at 230 degrees Celsius (450 degrees Fahrenheit) in a preheated oven till the cheese melts.
  • Place the cheese toasts on the soup.
  • Serve hot. Garnish with some parsley or chives while serving.

Notes

  • Herbs: Herbs like rosemary or parsley can be skipped completely. Fresh thyme can also be added instead of rosemary. 
  • Onions: Slice the onions thinly and evenly. You can use any variety of onions like red onions, white onions, yellow onions or shallots. 
  • Vegetable stock: Avoid using packaged stock having a high sodium content. It is better to make vegetable stock and use it in the recipe. 
  • Flour: You can either whole wheat flour or all-purpose flour. 
  • On caramelizing onions: For the soup to have a truly authentic and great flavor, it is important to caramelize the onions really well. So use a heavy pan or pot. Stir often when sauteing the onions. Toward the end stage when the onions become light golden, you have to stir often so that the onions get an even golden color and do not burn or darken. So stirring and cooking onions on a low to medium-low flame is the key. Even a slight burning of the onions will ruin the entire soup. 
  • Wine: You can use sherry wine or dry white wine. You can even use red wine. If you do not plan to add wine, then use vinegar. I suggest ½ to 1 tablespoon (depending on your taste) of white wine vinegar, red wine vinegar or apple cider vinegar. 
  • Gluten-free option: For the bread, use a gluten-free bread.
  • Cheese: Apart from Gruyere cheese, you can also add a vegetarian Parmesan cheese. 
  • Vegan option: Replace with a vegan butter or olive oil or neutral flavored oil and vegan cheese. 

Nutrition Info (Approximate Values)

Nutrition Facts
French Onion Soup
Amount Per Serving
Calories 519 Calories from Fat 198
% Daily Value*
Fat 22g34%
Saturated Fat 13g81%
Cholesterol 63mg21%
Sodium 1645mg72%
Potassium 360mg10%
Carbohydrates 60g20%
Fiber 5g21%
Sugar 11g12%
Protein 19g38%
Vitamin A 1214IU24%
Vitamin B1 (Thiamine) 1mg67%
Vitamin B2 (Riboflavin) 1mg59%
Vitamin B3 (Niacin) 4mg20%
Vitamin B6 1mg50%
Vitamin B12 1µg17%
Vitamin C 12mg15%
Vitamin D 1µg7%
Vitamin E 1mg7%
Vitamin K 4µg4%
Calcium 368mg37%
Vitamin B9 (Folate) 134µg34%
Iron 3mg17%
Magnesium 52mg13%
Phosphorus 321mg32%
Zinc 2mg13%
* Percent Daily Values are based on a 2000 calorie diet.

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Meet Dassana

Welcome to Dassana's Veg Recipes. I share vegetarian recipes from India & around the World. Having been cooking for decades and with a professional background in cooking & baking, I help you to make your cooking journey easier with my tried and tested recipes showcased with step by step photos & plenty of tips & suggestions.

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