Chicken Breast in Sour Cream

4 t. butter, melted
6 chicken breast halves (about 3 pounds)
1 T. olive oil
1/2 cup celery, chopped
1/2 bell pepper, chopped
1 zucchini, chopped
1 cup sour cream
1 t. salt
1/2 cup onion, chopped
1/4 t. pepper

Saute chicken in butter until lightly browned. Arrange chicken in a lightly greased ( with olive or coconut oil) casserole dish. Set aside. Saute onion, celery, zucchini and bell pepper in olive oil until tender. Remove from heat and let cool slightly. Combing the vegetables, sour cream, salt and pepper. Spoon mixture over chicken. Cover an bake at 350 degrees for 45 to 55 minutes, until chicken is cooked through.