1. Preheat oven to 350 degrees F. Grease a 2-quart casserole.
2. Mix together rice, corn, garlic, green onion, milk, chili powder, red-pepper seasoning, salt, pepper and 1-1/2 cups Cheddar cheese. Pour into casserole. Arrange tomato slices on top, overlapping slightly.
3. Bake in preheated 350 degree F oven until heated through, 35 to 40 minutes. Sprinkle with remaining 1/2 cup cheese for last 5 minutes of cooking. Let stand for 10 minutes before serving.