French Onion Soup
This French onion soup recipe is built on deeply caramelized onions, a rich beef broth, and a thick cap of melted Gruyère over toasted baguette. It takes time, but almost none of that time is hands-on labor.
Equipment
- Dutch oven - large, at least 6 quarts, heavy-bottomed
- Chef's knife - sharp
- Wooden spoon - sturdy
- Box Cheese Grater
- French Onion Soup Crocks - oven-safe
- Rimmed baking sheet
- Ladle
- Oven mitts
Ingredients
- 6 large yellow onions - about 3.5 lbs or 1.6 kg, thinly sliced into half-moons
- 4 tablespoons unsalted butter - 56g
- 1 tablespoon olive oil
- 1 teaspoon kosher salt
- 1/2 teaspoon granulated sugar - helps the onions caramelize evenly
- 2 cloves garlic - minced
- 1/4 cup dry sherry - 60ml
- 8 cups beef broth - 1.9 liters, preferably low-sodium
- 2 sprigs fresh thyme - or 1/2 teaspoon dried thyme
- 2 bay leaves
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon black pepper - freshly ground
For the Topping
- 1 baguette - sliced into 1/2-inch rounds
- 2 cups Gruyère cheese - 200g, shredded
- 1/2 cup Parmesan cheese - 50g, grated (optional)
Instructions
- Peel all onions, trim ends, cut in half from root to stem, and slice into thin half-moons about 1/8 inch thick.
- Melt butter with olive oil in a large Dutch oven over medium heat. Add onions, salt, and sugar, stir to coat. Cook uncovered for 15-20 minutes, stirring occasionally, until softened and translucent.
- Reduce heat to medium-low and continue cooking for 35-45 minutes, stirring more frequently as they darken. Scrape up browned bits from the pot. Add a tablespoon or two of water if sticking or browning too fast. The onions are ready when they are a deep amber brown and smell sweet.
- Stir in minced garlic and cook for 1 minute until fragrant. Pour in dry sherry, raise heat to medium-high, and scrape the pot constantly. Cook for 2-3 minutes until most of the sherry has reduced and the onions look glossy.
- Pour in the beef broth, then add thyme sprigs, bay leaves, Worcestershire sauce, and black pepper. Bring to a gentle boil, then reduce heat to low and simmer uncovered for 25-30 minutes. Taste and adjust salt if needed, then remove and discard bay leaves and thyme stems.
- While soup simmers, preheat oven to 400°F (200°C). Arrange baguette slices on a baking sheet and bake for 8-10 minutes, flipping halfway, until golden and crisp.
- Set oven's broiler to high and position rack about 6 inches from heat. Place soup crocks on a rimmed baking sheet. Ladle hot soup into each crock. Top with toasted baguette slices, cover generously with shredded Gruyère, and sprinkle with Parmesan if using. Broil for 2-4 minutes until cheese is bubbling and lightly browned. Serve immediately.
Notes
- Slice onions evenly so they cook at the same rate to avoid burning.
- Do not rush the caramelizing step; 45 minutes is normal and necessary for deep flavor.
- Use a high-quality beef broth that you would enjoy drinking on its own for the best results.
- Shred your own Gruyère cheese from a wedge for superior melting and flavor.
- Toast the bread separately to prevent it from becoming mushy before broiling.
- Watch the soup carefully under the broiler, as cheese can burn quickly.
- Make the soup base a day ahead to allow flavors to meld, then reheat and broil with fresh toppings just before serving.
- For a vegetarian version, substitute beef broth with rich vegetable or mushroom broth.
- The soup base (without bread and cheese) can be frozen for up to 3 months.
- Use dry sherry, white wine, or a splash of sherry vinegar mixed with extra broth as a substitute for deglazing.
Nutrition
Serving: 1servingCalories: 385kcalCarbohydrates: 32gProtein: 17gFat: 20gSaturated Fat: 11gPolyunsaturated Fat: 1gMonounsaturated Fat: 6gCholesterol: 55mgSodium: 1180mgPotassium: 420mgFiber: 3gSugar: 9gVitamin A: 10IUVitamin C: 15mgCalcium: 25mgIron: 8mg
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