French Onion Soup

Ingredients

• 4 tablespoons unsalted butter
• 12 pieces large onion
• 1/2 cup white wine
• 6 cups low sodium beef broth
• 1 tablespoon white wine vinegar
• 1 tablespoon dried thyme
• 1 teaspoon salt
• 1 teaspoon freshly ground pepper
• 4 cups cubed French bread
• 1/4 cup extra virgin olive oil
• 1 cup shredded mozzarelle cheese