In a skillet melt butter. Brown and cook chicken at medium high heat until tender, about ten minutes. Transfer to a baking dish or heatproof serving dish.
In skillet drippings, cook mushrooms until slightly brown, about five minutes. Remove from pan. Cook shrimp in skillet until pink, about five minutes. Remove from pan.
In a small bowl, combine water, bouillon and flour and stir into drippings in skillet. Gradually add half and half and champagne. Cook until thickened and bubbly. Spoon sauce, mushrooms and shrimp over chicken.
Bake in a 400 degrees oven for about twenty minutes or until chicken is tender.