1 lb. fresh mushrooms
4 tbsp. butter
4 tbsp. butter
2 c. milk or light cream
1/8 tsp. pepper
1 sm. onion, chopped
1 c. chicken stock
3 tbsp. flour
1/2 tsp. salt
1 1/2 c. sour cream

Saute mushrooms and onion in 4 tablespoons butter. Cook slowly for 20 minutes, stirring regularly. Add chicken stock. Melt over low heat the other 4 tablespoons butter. Add flour and cook for 5 minutes, stirring. Add milk and cream slowly and stir until thickened and smooth. Add salt and pepper. Stir in the mushrooms, onion, and chicken stock. Slowly add the sour cream, which has been brought to room temperature.