In a saute pan, turn to medium heat and ground the beef (or turkey) until mostly cooked and browned. If there is too many juices and fasts from the meat, drain some of that and discard. To the ground meat, add the taco seasoning (enough to coat all of the meat). Add the frozen corn to the meat and stir. Add the black beans that have been drained from their can. Let the mixture simmer on low heat while you prepare the taco ingredients. Shred the lettuce, shred the cheese and then serve the taco meat in a taco shell or tortilla. Serve with the lettuce, salsa, cheese, and sour cream. Garnish with cilantro if you wish.