1 lb uncooked macaroni (or other interesting pasta)
8 - 10 oz grated cheese(s). A nice variety of dry aged cheddars, swiss, curds, parmesan, etc. Just make sure they have a good strong flavor.
2 cups milk
4 tbsp butter
5 tbsp AP flour
1/2 tsp dry mustard
1/8(ish) tsp fresh grated nutmeg
salt and pepper to taste
Method
Cook the pasta per instructions on package, though you may want to stop about 1 minute short just so it is barely al dente.
While the pasta is cooking, in a 2 quart sauce pan melt your butter. Add the flour and whisk well. Allow to cook on medium high continually whisking until the flour mixture just begins to brown. Add the milk, salt, pepper, mustard and nutmeg. Turn the temperature down to a low medium. Continue whisking until the mixture thickens and barely comes to a boil. Remove from heat.
Add the cheese in thirds, stirring well until cheese melts before adding more. Remember, if you are using curds as one of your cheeses then they won't melt.
At this point, if everything has gone along smoothly, your pasta should be ready. Drain and put back into the original pot. Scrape the sauce over the pasta and stir well. Allow to rest for a few minutes and taste for seasoning. It usually needs a bit more salt, but make sure by tasting.
At this point some people like to put it into a casserole and bake with a crunchy top. If that's your thing..go for it. I personally just like to stand at the stove and eat it with a large spoon.