My Favorite Longhorn French Onion Soup Recipe

Ingredients

• 4 large yellow onions, thinly sliced
• 4 tbsp unsalted butter
• 2 tbsp olive oil
• 1 tbsp granulated sugar
• 4 cloves garlic, minced
• 8 cups low-sodium beef broth
• 1 cup dry sherry or white wine
• 2 sprigs fresh thyme or 1 tsp dried thyme
• Salt and pepper to taste
• 4 slices of baguette, about 1 inch thick
• 2 cups shredded Gruyère cheese
• 1 cup shredded mozzarella cheese (optional)