Classic French Onion Soup
Equipment
- 6 Oven-safe individual bowls
Ingredients
4-6 large yellow onions (about 1-1.2 kg / 2.2-2.6 lbs), thinly sliced
50 grams (about 3.5 tbsp) butter
1-2 tablespoons olive oil
1 teaspoon sugar (optional, helps with caramelization)
1/2 teaspoon salt (plus more to taste)
1/4 teaspoon ground black pepper
2-3 cloves garlic, minced
2 tablespoons all-purpose flour
1/2 cup (120 ml) dry white wine (like Sauvignon Blanc) or dry sherry/brandy/cognac
6 cups (approx. 1.5 liters / 1.6 quarts) good quality beef broth (can also use chicken or vegetable broth for a vegetarian version, though the flavor will differ)
2-3 sprigs fresh thyme
1 bay leaf
For the Croutons and Cheese:
4-6 thick slices (about 1.5-2 cm / 0.6-0.8 inches) of baguette (preferably slightly stale, day-old)
1 clove garlic, halved (optional)
1-1.5 cups (about 100-150 grams / 3.5-5.3 oz) coarsely grated Gruyère cheese (can also mix with Emmental, Provolone, or other good melting Swiss-style cheese)
Instructions
Prepare the Onions: Peel the onions and slice them thinly (about 3-5 mm / 1/8-1/4 inch thick).
Start Caramelizing: In a large, heavy-bottomed pot or Dutch oven, melt the butter with the olive oil over medium-low heat. Add the sliced onions, salt, pepper, and sugar (if using). Stir well to coat the onions in the fat.
Caramelize the Onions (The Important & Long Step): Reduce the heat to low. Cook the onions slowly and patiently, stirring occasionally (every 10-15 minutes at first, more frequently towards the end), for at least 45-60 minutes, or until the onions are very soft, significantly reduced in volume, and have turned a deep amber-brown color with a sweet, caramelized aroma. Be careful not to burn them! If they start sticking or browning too quickly, lower the heat further or add a tablespoon of water.
Add Garlic and Flour: Once the onions are well caramelized, increase the heat slightly to medium-low. Add the minced garlic and cook for about 1 minute until fragrant. Sprinkle the flour over the onions and stir well. Cook, stirring constantly, for another 1-2 minutes (this creates a light roux to thicken the soup).
Deglaze and Add Liquids: Pour the white wine (or brandy/sherry) into the pot. Using a wooden spoon, scrape up any tasty browned bits (fond) stuck to the bottom of the pot. Bring to a simmer and cook for 2-3 minutes until most of the alcohol has evaporated.
Add Broth and Seasoning: Add the beef broth, thyme sprigs, and bay leaf to the pot. Bring to a boil.
Simmer the Soup: Lower the heat, partially cover the pot, and simmer gently for at least 30 minutes to allow the flavors to meld. Taste and adjust seasoning (salt and pepper) as needed. Remove the thyme sprigs and bay leaf before serving.
Prepare the Croutons: While the soup simmers, preheat your oven to 180°C (350°F) or turn on the broiler (grill). (Optional: Lightly rub each baguette slice with the cut side of the garlic clove). Toast the baguette slices in the oven or on a dry pan until they are dry and lightly golden on both sides.
Assemble and Final Bake: Preheat the oven’s broiler (grill) to high. Ladle the hot soup into oven-safe individual bowls. Place one or two toasted baguette slices on top of the soup in each bowl. Generously sprinkle the grated Gruyère cheese over the crouton(s) and soup.
Broil until Golden: Carefully place the bowls on a baking sheet (to catch any spills). Place under the hot broiler for 2-5 minutes, or until the cheese is melted, bubbly, and nicely browned. Watch closely to prevent the cheese from burning!
Serve: Very carefully remove the extremely hot bowls from the oven (use oven mitts!). Let them rest for a minute or two before serving.
Notes
- Patience is Key: Don’t rush the onion caramelization. This step gives the soup its depth of flavor.
- Quality Broth: Use the best quality beef broth you can find or make your own.
- Cheese Variety: Feel free to mix Gruyère with Emmental or Provolone.
- Alcohol Boost: A splash of brandy or cognac stirred in at the very end of cooking (just before serving) can add another layer of flavor.
- Vegetarian Version: Use a rich vegetable broth instead of beef broth. Adding a splash of soy sauce or some rehydrated dried mushrooms can help deepen the umami flavor.