This french onion soup is designed to be dependable, flexible, and easy to serve. The ingredient list uses familiar supermarket items, while the notes explain where timing and technique matter most.
Why this recipe works
- Slow caramelization develops sweetness and complexity without relying on added sugar.
- A wide pot gives onions room to release moisture and brown evenly.
- Toasting the bread first helps it float and prevents immediate sogginess.
Ingredients
- 4 tbsp (56 g) butter
- 1 tbsp olive oil
- 3 lb (1.36 kg) yellow onions, thinly sliced
- 1 tsp salt
- 1/2 tsp sugar
- 2 garlic cloves, minced
- 1/3 cup (80 mL) dry white wine or extra broth
- 8 cups (1.9 L) beef broth
- 1 tsp fresh thyme leaves
- 1 bay leaf
- 1 tbsp Worcestershire sauce
- 6 thick slices baguette, toasted
- 1 1/2 cups (170 g) grated Gruyère or Swiss cheese
Step-by-step instructions
- Melt butter with oil in a wide heavy pot. Add onions and salt. Cook over medium-low heat for 45 to 60 minutes, stirring more often as they darken.
- When the onions are deep golden brown, add sugar and garlic. Cook for 1 minute, then deglaze with wine or broth, scraping the pot.
- Add beef broth, thyme, bay leaf, and Worcestershire sauce. Simmer uncovered for 25 minutes. Taste and adjust seasoning.
- Ladle into oven-safe bowls, top with toasted bread and cheese, then broil until bubbling and browned. Use care because the bowls become extremely hot.
Food safety: Use a food thermometer for meat and poultry, refrigerate perishable leftovers promptly, and reheat cooked leftovers to 165°F (74°C).
Cook’s notes
- Do not rush the onions with high heat; burnt edges make the soup bitter.
- No oven-safe bowls? Melt cheese on toast separately and place it on each serving.
- Broths vary in salt, so season only after simmering.
Substitutions and variations
- Use chicken broth for a lighter flavour.
- Add a teaspoon of balsamic vinegar at the end for extra depth.
- Use provolone or a mix of Swiss and mozzarella if Gruyère is unavailable.
What to serve with it
- A simple green salad
- Roasted mushrooms
- Fresh fruit after the meal
Storage and reheating
Refrigerate the soup base for 3 to 4 days or freeze for up to 3 months. Store bread and cheese separately.
Frequently asked questions
How dark should the onions be?
Aim for an even deep amber colour, not blackened edges. The process commonly takes close to an hour.
Can I make the base ahead?
Yes. Prepare the onion broth up to 3 days ahead, then toast and broil the toppings just before serving.
Is wine required?
No. Use additional broth and a teaspoon of lemon juice or mild vinegar for balance.