1Prepare Vinaigrette Dressing. Cut mozzarella in 1/4-inch slices. Cut tomatoes into 1/4-inch slices. Alternate mozzarella slices, tomato slices and basil leaves, overlapping on plate. Drizzle with dressing; sprinkle with salt and pepper.
Whisk vinegar, mustard, salt, pepper and sugar in small bowl until smooth. Refrigerate until ready to use. Whisk again before serving.