1 c. finely chopped walnuts
1/2 c. Parmesan cheese
1/2 c. chopped onion
1 stick butter
1/2 tsp. salt and pepper
1/2 c. sour cream

Mixture can be made ahead and frozen. Defrost day of use.

(Enough for 40 mushrooms, wash and take stems out)

1. Melt butter, saute onion until limp. 2. Remove onion from pan, leave butter in. 3. Add walnuts and saute for 5 minutes. 4. Add all ingredients together mixing well and fill mushroom cavity. Pour a bit of oil over each. 5. Bake at 350 degrees for 15 minutes.