Seed and chop the tomatoes. Place into a large bowl. Add the chopped garlic, onion, parsley, pepper, lemon juice, vegetable oil, and sweetener to the tomatoes. Mix well and set aside. Cook the black beans until done but not mushy. Drain well and add the frozen corn kernels. Cool to room temperature and combine with the tomato mixture. Allow to marinate for several hours. (Optional seasonings: chili powder or substitute cilantro in place of parsley.) Serving suggestions: as a dip for baked chips, rolled into a flour tortilla, as a topping over shredded lettuce or as a side dish.