Mix together in baking dish cooked noodles, cheese and butter or margarine.
In separate bowl beat eggs. Add milk, salt and pepper.
Pour egg/milk mixture over the noodles/cheese and stir.
bake uncovered in a preheated 375-400 degree oven until done (approx. 30 minutes). Note: some people prefer this to be creamy and some people prefer this to be a little on the dry side. Bake as you prefer. Also I like to stir my casserole about half way through the baking to distribute the cheese.