before serving.
Preheat oven to 350 degrees F.
In a large pot of boiling, salted water cook the pasta to cook.
While the pasta is cooking, in a separate pot, melt the butter. Temper in the egg. Stir in 3/4 of the cheese. Season with salt and pepper. Fold the macaroni into the mix and pour into a 2-quart casserole dish. Top with remaining cheese.
Melt the butter in a sauté pan . Bake for 30 minutes. Remove from oven and rest for five minutes