Bring 3+ quarts water to a boil; add 1 tbsp. salt and the macaroni and boil rapidly,uncovered, stirring occasionally until tender to a fork(7 to 9 minutes). Drain; rinse with hot water ;drain again.

Melt butter in a large fry pan. Add onion, green ppepper and saute until onion is golden. Remove with a slotted spoon and set aside. Now brown the beef and saute until meat is cooked. Return onion and pepper to the pan;add the mushroom sauce and cooked macaroni. Bring to a boil and simmer, uncovered, for 5 minutes. Serves 4 to 6.