Boil macaroni in water until tender and drain thoroughly. Stir in butter and egg.

Mix mustard and salt with Worcestershire sauce and add to milk.

Add cheese, leaving enough to sprinkle on top.

Pour into buttered casserole; add milk and sprinkle with cheese.

Add paprika.

Bake at 350 degrees for about 45 minutes or until custard is set and top is crusty.