– Hands-Off Cooking. The slow cooker does all the heavy lifting, making it perfect for busy days.
– Rich and Flavorful. Caramelized onions simmered in a rich broth create a deep and satisfying flavor.
– Elegant Yet Easy. Impress your guests with this French bistro favorite without spending hours at the stove.
In a large skillet, melt the butter over medium heat. Add the sliced onions and cook until they turn a deep golden brown, about 20-25 minutes, stirring occasionally. This step develops the soup's rich flavor, so don’t rush it.
Transfer the caramelized onions to your slow cooker. Add the beef broth, dry white wine, bay leaves, and fresh thyme. Season with salt and pepper. Stir to combine.
Ladle the soup into oven-safe bowls. Top each bowl with a slice of toasted bread and a generous amount of Gruyère cheese. Place the bowls under the broiler until the cheese is bubbly and golden brown.