This is a VERY easy recipe that I've served at many parties. It's always a hit and they go quickly! For 50 mushrooms, use 3/4 cup breadcrumbs, 1.5 cup cheddar, 1.5 tsp tarragon, 3/4 cup green onions and 6 Tbs butter. It took me a couple of years to figure that one out! Enjoy.