Corn, Avocado, and Tomato Salad

Combine the cooked corn (see note on how to cook), tomatoes and onion in a large glass bowl. Mix together the dressing ingredients in another bowl, pour over the salad, and gently toss to mix. Chill salad for an hour or two to let flavors blend. Add avocados right before serving so they don't brown. Adding a squirt of lime directly to them will help them not brown.