French Onion Soup Recipe with Gruyère Toasts

Name: French Onion Soup Recipe with Gruyère Toasts
Prep time: 15 min
Cook time: 75 min
Total time: 90 min
Yield: 4 servings
Cuisine: French
Ingredients: 1 kg yellow onions, thinly sliced; 50 g unsalted butter; 1 tsp granulated sugar; 1 tsp fine salt; 1/4 tsp black pepper; 1 l beef or vegetable broth; 150 ml dry white wine; 8 slices baguette; 200 g Gruyère or Emmental, grated; 2 sprigs fresh thyme

Rich caramelized onion soup topped with toasted baguette and melted Gruyère.

By Savva LoginovUpdated October 2, 2026

Total 1 hr 30 minMakes 4 servings

Jump to Recipe

Slow-caramelized onions form the base of this French onion soup, enriched with broth and white wine. Toast baguette slices with cheese separately, then place them over bowls just before serving. Melt butter in a heavy pot over medium-low heat. Add onions, sugar and salt. Cook 35 to 45 minutes, stirring often, until deep golden. Pour in wine and scrape browned bits. Simmer 5 minutes. Add broth, pepper and thyme. Simmer gently 20 minutes; remove thyme stems. Heat oven to 180°C (350°F). Top baguette slices with grated cheese and bake 5 to 7 minutes until melted and golden. Ladle soup into bowls and top with cheesy toasts.

French Onion Soup Recipe with Gruyère Toasts

How to tell when it is ready

Cook until tender, set or golden as described.

Tips

Measure ingredients before beginning.
Use even-sized pieces for consistent cooking.
Taste and adjust seasoning near the end.
Cool and store leftovers promptly.

Troubleshooting

If mixture is too thick, add liquid gradually.
If browning too quickly, lower the heat.

Substitutions

Use a suitable neutral oil if needed.
Choose compatible alternatives for dietary needs.

Variations

Adjust spices to your preference.
Add citrus zest for a brighter flavor.

Serving suggestions

Serve with a fresh seasonal side.
Pair with tea, coffee or a suitable drink.
Offer a complementary sauce or topping.
Serve warm or chilled as directed.

Make ahead

Measure ingredients ahead and refrigerate perishable components; finish shortly before serving.

Storage

Refrigerate leftovers promptly and use within 3 days.

Food safety

Contains dairy and gluten. Use broth suited to dietary needs.

Frequently asked questions

Can I prepare this ahead?

Prepare components ahead and refrigerate promptly.

How should I store french onion soup with gruyère toasts?

Refrigerate leftovers promptly and use within 3 days.

Serve promptly and store leftovers safely.

About the author

Savva Loginov

Savva Loginov writes about traditional Ukrainian cooking, including regional dishes, heritage baking and the customs behind familiar recipes. His English guides explain each dish’s context alongside clear, practical cooking instructions.

French Onion Soup Recipe with Gruyère Toasts