Spread center of double layer of aluminum foil with 1/2 tablespoon of butter. Top with 1/3 tomato slices, sprinkle with 1/3 each of cheese, basil, salt and pepper. Repeat layers, ending with pepper. Dot top with remaining butter. Seal foil around tomatoes. Place tomatoes on Step-Up-Grid over low heat in covered grill and cook for 20-30 minutes.
There's no better way to take advantage of the seasonal abundance of garden tomatoes.