Add seasonings, lime juice, and black beans. Turn heat to high and cook until thoroughly heated (about 2 minutes).
Stir in tomatoes. Remove from heat.
Divide polenta among four plates or shallow bowls, spoon bean mixture over polenta and top with cilantro and other desired toppings.Serve hot.
Notes
The amount of salt needed will vary greatly depending on how much salt is in your beans.Yield: 5 cups cooked polenta + 2 1/2 to 3 cups bean topping (2 to 4 servings)