French Onion Soup

Ingredients

• 1 tablespoon olive oil
• 6 cups thinly sliced onions
• 1/2 pound sliced baby portabellas
• 1 teaspoon sugar
• 4 cloves garlic, peeled and sliced
• 1/4 cup sherry
• 1 tablespoon Dijon mustard
• 1/2 teaspoon dried thyme leaves
• 2 tablespoons all-purpose flour
• 6 cups beef broth
• 1 cup white wine or cooking wine
• Salt
• pepper
• 8 (1/2-inch thick) slices French bread, toasted
• 1 cup shredded part-skim mozzarella cheese
• 1/2 cup grated Parmesan cheese