preheat oven to *350- clean mushrooms & carve out stem, turning caps into bowls. pour melted butter into 13 x 9- inch baking dish. put mushrooms, caps down, in dish and swirl around in butter, making sure the mushrooms won't stick. mix together rest of ingredients & scoop into large zip-loc bag. seal bag & cut off small amount of bag from tip. pipe filling into mushroom 'bowls'
bake 30 minutes, until mushrooms are tender. sprinkle any kind of shredded cheese on top & bake 10 more minutes, until golden brown. serve immediately