Chicken Tam O'Shanter

2 tablespoons oil
2 tablespoons butter
1 broiler-fryer chicken, cut up
1 small onion, finely chopped
1/4 pound mushrooms, sliced
1/4 cup Johnnie Walker Red, warmed
1/2 cup chicken broth or bouillon
1 cup sour cream (at room temperature)
Pepper, to taste

Heat oil and butter in large skillet. Add chicken pieces; saut