In a saucepan, sauté:

2 tbsp butter

2-3 oz mushrooms (chop fine)

1/4 cup chopped onions

a couple sprigs chopped parsley

1 tbsp capers

salt and pepper to taste

When onions are tender, stir-in 1 tbsp flour

Then add:

1 cup chicken broth

1/2 cup sour cream