Makes 4 servings
1 loaf (14-16 ounces) ciabatta bread or other wide, flat loaf
2-3 tomatoes, thinly slices
12 ounces fresh mozzarella cheese, sliced
20 fresh basil leaves
2 tablespoons balsamic vinaigrette dressing (or whisk together 1 tablespoon olive oil and 1 tablespoon balsamic vinegar)
1/2 sweet yellow onion, halved and thinly sliced (optional)
1. Slice the loaf in half, separating the top from the bottom. On the bottom half, put a layer of cheese, followed by the tomatoes and basil.
2. Top the fillings with the vinaigrette dressing, and add the onions, if desired. Put the other half of the bread on top of the fillings and slice the sandwich into 4 pieces to serve.