In a large pot of salted water, lightly boil the macaroni for about 5 minutes until half-cooked.
Whisk the egg and milk together in a large cup. Add butter and cheese to the egg and milk. Stir well.
Lightly grease a medium baking dish and place the lightly cooked macaroni in it. Pour the egg and cheese mixture over the macaroni, sprinkle with salt and pepper, and stir well. Press the mixture evenly around the baking dish.
Bake uncovered for 30 to 40 minutes, or until the top is brown.