3 whole chicken breasts -- halved

2 tablespoons margarine

1 can condensed cream of chicken soup

1/2 cup dry sherry

1 teaspoon leaf tarragon or leaf rosemary

1 teaspoon Worcestershire sauce

1/4 teaspoon garlic powder

1 can sliced mushrooms (4 oz) -- drained

Rinse chicken breasts and pat dry; place in crock pot. In saucepan, combine remaining ingredients and heat until smooth and hot. Pour over chicken breasts. Cover and Cook on low setting for 8 to 10 hours.