3 tbsp. butter
1 c. thinly sliced lg. onion
1 1/2 lbs. mushrooms, sliced
1 tsp. salt
Dash pepper
1/2 tsp. Worcestershire sauce
1 tbsp. lemon juice
1/2 lb. Swiss cheese, shredded
1 egg yolk
1 tbsp. water

Melt butter in skillet on medium heat. Add onion, cook 2 minutes. Add mushrooms, salt, pepper, Worcestershire sauce and lemon juice. Cook 5 minutes, stirring occasionally. Drain. Prepare pie shell, rolling 3/4 of dough for 9" pie and allow 1" overhang. Roll remaining dough and cut into 1/2" wide strips, about 8 or 10 of them.

Combine cheese and mushroom mix and mix well. Turn into shell. Arrange pastry strips lattice fashion on top of filling. Trim ends even with edge of shell moisten. Fold overhang over strips and flute edges. Beat egg yolk and water. Brush over pastry. Bake in 350 degree preheated oven for 35 to 40 minutes or until golden brown. May be served hot or cold.