Classic French Onion Soup Pack: A Cozy Recipe - Crock Recipes

Ingredients

• 4 large onions, thinly sliced
• 4 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 teaspoons salt
• 1 teaspoon sugar
• 8 cups beef broth, preferably low-sodium
• 1 teaspoon fresh thyme
• ½ cup dry white wine, optional
• Freshly ground black pepper, to taste
• 4 slices of crusty French bread
• 1 ½ cups shredded Gruyère cheese
• ¼ cup grated Parmesan cheese, optional