All you need:
Cook your macaroni, for three people and leftovers for lunch I cook half a box.
Grease a baking dish and pour the cooked macaroni in. Pour milk to about the halfway point of the macaroni.
Cover with velvetta, in my opinion, the more the better.
Cover with foil. (Word to the wise, don't uncover while cooking, it causes the mac to dry out.)
Cook at 350 for about 40mins.
Stir and enjoy.