Sprinkle chicken with salt and pepper; sauté on all sides in melted butter until brown. Remove chicken from skillet, and set aside.
Add onion, green pepper, and garlic to skillet; sauté until tender. Stir in next 9 ingredients; add chicken. Reduce heat, and cook, covered, 45 minutes or until chicken is tender. Remove chicken to serving platter, and keep warm.
Combine cornstarch and water; mix well. Add to sauce in skillet; cook, stirring constantly, until thickened and bubbly. Spoon sauce over chicken.