Preheat oven to 350 degrees F. Boil ramen noodles until cooked, drain, set aside (do not add seasoning).
In skillet, combine butter, mushrooms and chicken. Sautee until chicken is browned. Add water, and seasoning packets from noodles. Let simmer for about 5 minutes.
Remove from heat and place in casserole dish. Add sour cream to casserole dish, mix. Add noodles and steamed broccoli to casserole dish, toss until everything is evenly coated. Cover with bread crumbs and slices of cheese.