Servings: 4 servings.
6 tablespoons wasabi mayonnaise or plain mayonnaise 8 slices sourdough bread (1/2 inch thick), toasted 2 large heirloom tomatoes, sliced 1/2 teaspoon sea salt 1/2 teaspoon coarsely ground pepper 1/2 large sweet onion, thinly sliced 8 ounces fresh mozzarella cheese, sliced 1/2 cup fresh basil leaves
