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!
Mom dumps 3 lbs of onions in slow cooker overnight, makes irresistible meal
