Sweet, deeply browned onions and bubbling cheese make a bowl of soup feel like a proper sit-down dinner. Give the onions time to turn golden and jammy; that slow browning builds a rich broth without needing a long list of ingredients. Add a simple green salad, and dinner is ready for the table.
The featured image is an AI-generated serving illustration; the finished dish may differ.
French Onion Soup with Gruyère Toasts
Serves 4 | Prep: 15 minutes | Cook: 90 minutes | Total: 105 minutes
Ingredients
- 3 lb yellow onions (halved and thinly sliced about 1/8 inch thick)
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 1/2 tsp kosher salt
- 2 cloves garlic (minced)
- 1/2 cup dry white wine
- 6 cups low-sodium beef broth (from cartons)
- 4 sprigs fresh thyme
- 1 bay leaf
- 1/4 tsp black pepper (freshly ground)
- 8 slices baguette (cut 1/2 inch thick)
- 8 oz Gruyère cheese (coarsely grated, about 2 cups)
Instructions
- Melt the butter with the olive oil in a wide, heavy 6-quart Dutch oven over medium heat, about 2 minutes. Add the onions and salt, and toss to coat.
- Cook the onions uncovered for about 55 minutes, stirring every few minutes at first and more frequently as they darken. Adjust the heat between medium and medium-low so they brown without scorching. They should become very soft and deep golden brown, with a brown film on the bottom of the pot. If that film threatens to burn, loosen it with a small splash of the measured broth and scrape with a wooden spoon. Allow extra time if the onions are still pale.
- Stir in the garlic and cook for 1 minute. Add the wine and scrape up the browned bits from the bottom. Simmer for about 4 minutes, until the wine has reduced by roughly half.
- Add the remaining broth, thyme, bay leaf and pepper. Bring to a gentle simmer, then cook uncovered for 20 minutes, adjusting the heat to maintain small, steady bubbles. Remove the thyme stems and bay leaf. Taste and add salt and pepper as needed; low-sodium broths vary a lot.
- While the soup simmers, heat the oven to 425°F. Arrange the baguette slices on a rimmed baking sheet and bake for 8–10 minutes, turning halfway through, until dry and lightly golden on both sides. Remove the sheet from the oven.
- Switch the oven to high broil and allow about 5 minutes to heat, with a rack positioned so the bowl rims will sit about 6 inches below the element. Set four broiler-safe soup bowls, each with at least a 20-ounce capacity, on a sturdy rimmed baking sheet. Divide the hot soup among the bowls, leaving room for the toppings. Place two toasts on each bowl and divide the Gruyère evenly over them.
- Broil for 2–4 minutes, watching continuously, until the cheese is melted, bubbling and browned in spots. Use oven mitts to move the baking sheet and serve the bowls on heatproof plates, warning diners that the bowls are very hot.
Kitchen Tips
Keep hands and tools clean, rinse produce, and keep raw foods separate from ready-to-eat ingredients.
- A wide pot helps moisture escape so the onions brown rather than simply steam. A narrow pot may need more time.
- Do not rush the onions with high heat: dark, scorched edges make the broth bitter rather than richer.
- If you do not have broiler-safe bowls, broil the cheese directly on the toasted bread on the baking sheet, then slide two cheese toasts onto each bowl of hot soup.
Food Safety
- Wash hands with warm soapy water for at least 20 seconds before and after handling food. Clean tools, boards and counters with hot soapy water between food items.
- Rinse fresh fruits, vegetables and herbs under running water before peeling, cutting, zesting or juicing. Follow package directions for prewashed or ready-to-eat produce.
- Thaw frozen ingredients in the refrigerator, never on a counter.
Sources: FDA safe food handling and safe minimum cooking temperatures.
Variations
- For a meatless version, replace the beef broth with a rich vegetable or mushroom broth and choose a vegetarian-rennet Gruyère-style cheese.
- For a version without wine, use an additional 1/2 cup beef broth for deglazing and stir in 1 teaspoon sherry vinegar after simmering.
What to Serve With It
Serve with a crisp green salad dressed with mustard vinaigrette to balance the rich broth and cheese.
Storage and Reheating
Refrigerate or freeze perishables within 2 hours of cooking or purchase, or within 1 hour at 90 F (32 C) or hotter. Refrigerate promptly in shallow containers; do not wait for room temperature. Keep the refrigerator at 40 F (4 C) or below and use cooked leftovers within 4 days. If reheating leftovers, heat to 165 F (74 C).
Frequently Asked Questions
Can I make the soup ahead?
Yes. Make the soup through the simmering step and keep the toppings separate. Reheat as directed in the storage guidance, then toast the bread and finish the bowls under the broiler.
Why are my onions taking longer to brown?
Onions vary in moisture, and a crowded or narrow pot slows evaporation. Keep cooking until they are deeply golden and jammy rather than stopping at the clock.
Can I use a different cheese?
Comté or Swiss cheese can replace the Gruyère in the same quantity. Choose a cheese that melts smoothly and grate it yourself for an even topping.
This recipe was developed with AI assistance and has not been kitchen-tested. Check ingredient labels for allergens and use appropriate food-safety temperatures.
