This classic French Onion Soup recipe utilizes the slow cooker to achieve deeply caramelized, sweet onions that form the base of an aromatic beef broth.1 It is traditionally finished under the broiler with crunchy bread and melted Gruyère cheese.
Ingredients:
| INGREDIENTS | QUANTITY |
| Yellow onions, thinly sliced | 3 pounds |
| Unsalted butter, melted | 2 tablespoons |
| Olive oil | 2 tablespoons |
| Balsamic vinegar | 1/4 cup |
| Fresh thyme sprigs | 2 |
| Beef stock | 8 cups |
| Shredded Gruyere cheese | 1.5 cups |
| Salt and pepper | To your liking |
| Brandy | 1/3 cup (Optional) |
| Crunchy bread slices | To serve |
How To Make French Onion Soup:
- Step 1: Caramelizing the Onions: Pour the 3 pounds of sliced onions into your slow cooker. Drizzle in the 2 tablespoons melted butter and 2 tablespoons olive oil, and season with salt and pepper. Set to LOW and let it cook for 10-12 hours until the onions are deeply golden and caramelized.
- Step 2: Adding Flavor: Stir in the 8 cups beef stock, 1/4 cup balsamic vinegar, and the thyme leaves (removed from sprigs). Cook covered on LOW for another 6-8 hours. Season as needed, and feel free to add the 1/3 cup brandy (optional).
- Step 3: Preparing the Topping: Get your oven ready at 350°F (180°C). Spoon the soup into oven-proof bowls and place them on a baking sheet. Crown each bowl with toasted bread slices and a sprinkle of Gruyère cheese.
- Step 4: Bake and Broil: Bake for 20-30 minutes until the cheese melts. For an extra golden touch, broil for 2-3 minutes, watching carefully to prevent burning.
- Step 5: Serve and Enjoy: Once cooled a tad, dive into your comforting bowl of French Onion Soup!
