Vitello Foccacia

Name: Vitello Foccacia
Ingredients: 3/4 cup extra virgin olive oil, plus 2 T for sauteing onions and garlic; 1/4 cup balsamic vinegar; 2 tablespoons dijon mustard; 3 tablespoons mixed dried Italian herbs; 1 teaspoon freshly ground black pepper; 12 slices fresh mozzarella; 12 slices fresh tomato; 24 medium to large fresh basil leaves; 1 medium sized sweet onion, diced; 3 garlic cloves, chopped; 1/4 cup dry white wine; 1/4 pound hard salami, diced; 1/4 pound prosciutto, diced; 1/4 cup fresh Italian flat leaf parsley, chopped; 1 cup shredded fresh Parmesan; 3 pounds ground veal; 2 eggs, beaten; 12 pieces Italian flat bread, cut to size of hamburger buns, and sliced open; 1/2 stick butter, melted