Created by TeresaS on November 7, 2015
Step 1: To prepare the dressing, in a small bowl, whisk the vinegar, oil, sugar, salt, mustard and pepper.
Step 2: In a large salad bowl, combine the tomatoes, onions and basil.
Step 3: Drizzle with the dressing; toss to coat.
Step 4: Refrigerate, covered, tossing once, until the flavors are blended, at least 1 hour.