French Onion Soup

By Published On: February 19th, 2021

There are few soups quite like the sweet, umami delight that is a well, made deep and delicious French onion soup. Learn how to get the most flavour out of the humble onion with my recipe…

French Onion Soup with Gruyere Crouton

I can polish off a bowl of onion soup in the blink of an eye, I love it so much. The humble onion is elevated into new highs with this classic French recipe.

What makes French Onion Soup so special?

When cooked low and slow, onions take on an amazing umami sweetness that's something very special. A rich, creamy and decadent soup like no other. And it's such a humble dish too - few ingredients but BIG on flavour.

What kind of onions should I use?

I generally go for a large, sweet onion like a Vidalia or Walla Walla but generally, any yellow onion will do. On occasion I'll make it with red onion, as they're typically sweeter, but they're not strictly traditional for the French recipe. That said, use whatever you have!

Low and slow, extract all the flavour and colour.

First things first, we're going to cook the onion down slowly. This will ensure a great texture, colour and flavour - 30 minutes of slow sautéing will get the job done. I like to fry the onions in a little butter (because France) and inject a little herbal delight in the form of fresh thyme and a bay leaf.

Once you've melted down the onion, it's time to add a little garlic for flavour and then a good quality stock. Traditionally you can use either chicken or beef. Beef will give a meatier flavour, but a good homemade chicken stock is just as good - you can of course use store bought broth. But mark my words, a homemade stock is so much more flavourful!

An unauthentic twist! Soy sauce.

Now, this is probably going to fill my French readers with horror, but I do like to add a little dark soy sauce to my soup - so, before you leave in protest, hear me out! Soy sauce has a wonderful deep, rich colour which gives the soup a great deep hue, but also a rich, umami saltiness which adds a layer of flavour to the broth. I add around 1-2 tsp. It's obviously not traditional, but it works! It's also optional so don't sweat it if you're too horrified.

Once we've stewed the onions for a while it's done! You have a dark, golden soup that's packed with flavour. That's it - ready to serve... almost.

A good French Onion Soup Recipe isn't complete without the croutons to end all croutons. And by that I mean a slice of crusty bread toast with bubbling-hot Gruyère or Comté cheese on top. The cheese melts into the soup and the whole thing is an utter 'Triomphe!'.

This soup is a great lunch or dinner dish - filling, rich and completely delicious. Great in cold weather, hot weather, wet weather, dry weather. You get the picture.

More delicious soup recipes to try at home.

If you're in the mood for soup, you're at the right place! I love soups so much, I have collected my 10 Best Soup Recipes for your viewing pleasure. You're welcome.

More French Recipes

French Onion Soup

French Onion Soup

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5 from 2 votes
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Recipe by Lee
Course Appetizer, Main Course
Cuisine French
Prep Time10 minutes
Cook Time1 hour 10 minutes
Total Time1 hour 20 minutes
Servings (adjustable) 4
Calories (per serving) | 744


  • 3 lb yellow onion (peeled, halved and cut into thin half-moon slices)
  • 3 tbsp unsalted butter
  • 4 sprigs thyme
  • 1 bay leaf
  • 2 garlic cloves (peeled & finely chopped)
  • 2 qt chicken stock (or beef) around 2 litres
  • 2 tsp dark soy sauce (optional)
  • 2 tsp kosher or sea-salt
  • freshly ground black pepper
  • 4 crusty bread slices
  • 2 cups gruyere cheese (coarsely gated)


  • In a large pan, heat the butter until bubbling over a medium/high heat.
    Add the onion, thyme and bay leaf and stir well. Reduce the heat to medium/low and let them gently fry for 30 minutes, stirring regularly. They will soften and turn golden brown.
  • Add the garlic and fry for 1-2 minutes before adding the stock and soy sauce (if using). Season with the salt & pepper. Bring the soup to a boil then reuce the heat to low and simmer gently, uncovered for 30-40 minutes. Just bubbling.
  • Fish out the bay leaf and any thyme stalks and remove from the heat.
  • Preheat a grill/broiler until hot.
    In a toaster, toast the bread lightly. Meanwhile, spoon a portion of soup into a small bowl and place a slice of toast on top. Pile on about 1/2 cup cheese on the bread then place under the hot grill/broiler for 3-4 minutes until the cheese is completely melted and bubbling.
    Repeat with more soup/bread/cheese combos.
    Serve hot!


Calories: 744kcal (37%) | Carbohydrates: 65g (22%) | Protein: 39g (78%) | Fat: 37g (57%) | Saturated Fat: 20g (125%) | Trans Fat: 1g | Cholesterol: 109mg (36%) | Sodium: 1273mg (55%) | Potassium: 1102mg (31%) | Fiber: 7g (29%) | Sugar: 22g (24%) | Vitamin A: 958IU (19%) | Vitamin C: 28mg (34%) | Calcium: 794mg (79%) | Iron: 3mg (17%)
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French Onion Soup with Gruyere Crouton

Did you make my French Onion Soup?

How did you go? Let me know in the comments below and be sure to tag @cookeatworld at Instagram.