Remove stems of mushrooms and chop finely. Preheat oven to 350 degrees Fahrenheit and place caps on rack with the gills facing down. Bake for 7 minutes and remove from oven. Allow the caps to drain and cool for about an hour. Combine chopped stems with remaining ingredients and add a tablespoon and a half to each cap. Bake in preheated 350 degree oven for 22 minutes, then broil on high for about 2 minutes to brown tops (watch carefully)