In large frypan, place butter and oil and heat to medium temperature until butter melts. Add chicken and cook, turning, about 10 minutes or until brown on all sides. Remove chicken and place in baking pan or casserole. In same frypan, saute mushrooms about 5 minutes or until tender. Stir in flour. Add soup, wine and water; simmer, stirring, about 10 minutes or until sauce thickens. Stir in cream, salt, tarragon and pepper; pour over chicken. Bake, uncovered, in 350 degree F. oven for 60 minutes. Mix in artichoke hearts, green onions and parsley. Bake about 5 more minutes or until fork can be inserted in chicken with ease. Makes 4 servings.