Classic French Onion Soup

A restaurant-worthy French Onion Soup you can make at home, filled with rich flavour and finished with a cheesy, golden topping.

French Onion Soup is a timeless comfort dish, full of deep, savoury flavour in every spoonful. Slowly caramelised onions form a naturally sweet base, enhanced by rich beef stock and a hint of cognac for depth.

Julia Child once said, “I enjoy cooking with wine, sometimes I even put it in the food.” This recipe always reminds me of that quote, as the wine adds the signature richness and warmth that makes this soup so memorable.

Topped with crisp toasted bread and a bubbling layer of Gruyère cheese, this soup is hearty, rustic, and satisfying. It’s a classic you can easily recreate at home, bringing restaurant-quality flavour to your own kitchen.

Tips for Best Results

• Caramelise slowly: Take your time cooking the onions until they’re deeply golden brown for the best flavour. Rushing this step will leave them sharp and underdeveloped.
• Use warm stock: Adding warm stock prevents lumps when combined with the flour-coated onions.
• Choose the right cheese: Gruyère gives the perfect nutty, melty topping. Swiss cheese works well as a more budget-friendly option.
• Toast the bread well: Crisp bread holds up better in the soup, so toast it thoroughly before topping.
• Serve in oven-safe dishes: Cocottes or ovenproof bowls allow you to broil the cheese topping directly on the soup.

Ingredients and Substitutions

• Onions: Yellow onions are classic; red onions can be added for extra sweetness.
• Butter and oil: Butter adds richness; oil prevents burning. All butter is fine if preferred.
• Sugar: Helps to promote carmelisation of the onion, can be skipped.
• Flour: Slightly thickens the broth. Cornstarch can be used for a gluten-free option.
• Beef stock: Homemade or store-bought.
• Wine: Dry white wine or dry vermouth adds brightness and deepens the flavour.
• Cognac: Optional, enhances richness. Sherry or brandy works too.
• French bread: Sturdy baguette or country loaf is best. Gluten-free bread is fine.
• Gruyère cheese: Traditional; Swiss, Comté, or mozzarella can substitute.

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Classic French Onion Soup

Yields: 6 servings | Prep time: 20 minutes | Cook time: 1 hour 15 minutes

Ingredients:

• 3 tablespoons unsalted butter
• 1 tablespoon cooking oil
• 4-6 large yellow onions (about 2–3 lbs)
• 1 teaspoon salt, plus more to taste
• ½ teaspoon black pepper
• ½ teaspoon sugar
• 1 tablespoon all-purpose flour
• 6 cups beef stock (homemade or store-bought)
• 1 cup dry white wine (or dry vermouth)
• 2–3 tablespoons cognac (optional but recommended)
• 8 slices French bread (½–1 inch thick)
• 1½ cups grated Gruyère cheese (or Swiss)

Directions:

Slice the Onions

1. Cut off both the stem and root ends of each onion, then slice the onion in half from top to bottom. Peel away the papery skin.
2. Place each half flat side down on the cutting board for stability. Using a sharp chef’s knife, slice the onion lengthwise (from top to bottom) into thin, even slices about ⅛–¼ inch thick. (Image 1)

Softening the onions

1. In a heavy-bottomed pot or Dutch oven, melt butter with cooking oil over medium-low heat.
2. Add the sliced onions and 1 teaspoon salt. Stir to coat, cover, and cook for 20 minutes until soft. (Image 2)

Caramelize the onions

1. Remove the lid, add sugar, and continue cooking uncovered over medium heat. Stir frequently until the onions are deeply golden and caramelized (about 20–25 more minutes). (Image 3)

Add flour and deglaze

1. Sprinkle flour over the onions, stirring constantly for 2–3 minutes to remove the raw taste.
2. Gradually add 1 cup warm stock, scraping the bottom of the pot to release browned bits. (Image 4)

Build the soup

1. Add the remaining stock and wine. Bring to a simmer and cook for 20–30 minutes. (Image 5)
2. Optional: stir in cognac for extra depth of flavour. Taste and adjust salt and pepper.

Prepare the croutes

1. Preheat oven to 325°F (160°C).
2. Drizzle bread slices lightly with olive oil and toast on a baking sheet for 15 minutes per side until crisp. (Image 6)

Assemble in cocottes and broil

1. Ladle soup into individual cocottes.
2. Add a few tablespoons of Gruyère directly into the soup for extra richness.
3. Place toasted bread on top and cover generously with the remaining Gruyère. (Image 7 & 8)
4. Broil for 2–3 minutes until cheese is melted and golden brown. Watch carefully to avoid burning.

Continue to Content

Yield: 6 Servings

Classic French Onion Soup

Prep Time: 20 minutes

Cook Time: 1 hour 15 minutes

Total Time: 1 hour 35 minutes

A restaurant-worthy French Onion Soup you can make at home, filled with rich flavour and finished with a cheesy, golden topping.

Print

Ingredients

• 3 tablespoons unsalted butter
• 1 tablespoon cooking oil
• 4-6 large yellow onions (about 2–3 lbs)
• 1 teaspoon salt, plus more to taste
• ½ teaspoon black pepper
• ½ teaspoon sugar
• 1 tablespoon all-purpose flour
• 6 cups beef stock (homemade or store-bought)
• 1 cup dry white wine (or dry vermouth)
• 2–3 tablespoons cognac (optional but recommended)
• 8 slices French bread (½–1 inch thick)
• 1½ cups grated Gruyère cheese (or Swiss)

Instructions

1. Trim off both the stem and root ends of each onion.
2. Cut onions in half from top to bottom and peel away skins.
3. Place each half flat side down on the cutting board and slice lengthwise into thin, even slices about ⅛–¼ inch thick.
4. Melt the butter with the oil in a heavy-bottomed pot or Dutch oven over medium-low heat.
5. Add the sliced onions and 1 teaspoon of salt. Stir to coat, cover, and cook for 20 minutes until softened.
6. Remove the lid, add the sugar, and continue cooking uncovered over medium heat. Stir frequently until the onions are deeply golden and caramelized, about 20–25 minutes.
7. Sprinkle the flour over the onions and stir constantly for 2–3 minutes.
8. Slowly add 1 cup of warm stock, scraping the bottom of the pot to release browned bits.
9. Stir in the remaining stock and wine. Bring to a simmer and cook for 20–30 minutes.
10. Stir in the cognac, if using. Taste and adjust seasoning with salt and pepper.
11. Preheat the oven to 325°F (160°C).
12. Drizzle the bread slices lightly with olive oil and place on a baking sheet. Toast for 15 minutes per side until crisp.
13. Ladle the soup into individual cocottes.
14. Stir a small handful of Gruyère into each portion of soup.
15. Place toasted bread slices on top of the soup.
16. Cover the bread generously with the remaining Gruyère.
17. Place the cocottes under the broiler for 2–3 minutes until the cheese is melted and golden brown. Watch carefully to avoid burning.
18. Remove from the oven and let cool for 2–3 minutes before serving.

Recommended Products

As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.

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  ZWILLING Twin Signature 19-pc Kitchen Knife Set with Block
• 
  Le Creuset Stoneware Mini Round Cocotte
• 
  Amazon Basics Cast Iron Dutch Oven

Nutrition Information:

Yield:

6

Serving Size:

1½ cups soup + bread and cheese
Amount Per Serving: Calories: 759Total Fat: 22gSaturated Fat: 11gTrans Fat: 0gUnsaturated Fat: 10gCholesterol: 51mgSodium: 1795mgCarbohydrates: 81gFiber: 5gSugar: 14gProtein: 29g

This information is provided as a courtesy and for entertainment purposes only. This information comes from online calculators. Although frugalmomeh.com attempts to provide accurate nutritional information, these figures are only estimates.

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