This is a Rachel Ray recipe I got from a friend and, though it's not truly Mexican, I love it because every flavor is discernible and distinct, for a truly enjoyable culinary experience.
Combine the ingredients below and enjoy with tortilla chips or as a garnish with a meal.
1 1/2 large tomatoes (about 3/4 pound), cored and cut into small pieces
1 1/2 c. fresh or thawed and drained frozen corn
Half of a small onion, finely chopped
1/3 c. chopped fresh cilantro
3 Tb. red wine vinegar (or less white vinegar--but definitely best with red wine vinegar)
1 Tb. vegetable oil
(Salt and pepper to taste, optional)