1 lb. fresh mushrooms, cleaned and quartered
2 tbsp. butter
1/3 c. sour cream
Salt and pepper to taste
1 egg yolk
1/4 c. finely chopped parsley
1/2 c. grated Swiss cheese

Heat butter in large skillet. Saute mushrooms until lightly browned. Simmer 2 minutes.

Blend sour cream, egg yolk, salt and pepper until smooth. Add to mushrooms. Heat, stirring constantly, until blended. Remove from heat. Pour into a shallow baking pan. Sprinkle with parsley and cheese.

Before serving, place uncovered in 425 degree oven for 10 minutes or until mushrooms are heated and the cheese is melted.