SPREAD each cracker with pizza sauce and top with sliced pepperoni or ham and 2 mushroom slices.
SPRINKLE with shredded cheese.
BAKE at 350°F (180°C) for 3 to 5 minutes OR heat in covered BBQ over low heat for 2 to 3 minutes, until cheese melts OR microwave on MEDIUM about 30 seconds or until cheese melts.