Four Cheese Mac and Cheese

I'll admit I am yet to find what I consider the perfect cheese combo for homemade mac and cheese. I have determined that I like a little Gruyere, regardless of how expensive it is (you just need a little) and that (for textures sake) it really helps to have a little bit of American (I know, horrible stuff, but it helps). Other than that I use a cheddar base. The forth cheese is Parmesan - which I use in the topping. This recipe is a bit better if you replace the milk with half and half (duh) but I don't think it is necessary....of course even with regular milk this is not something you want to have for dinner every night! Everything in moderation right?

Pasta 16 oz. shape of your preference
Cheese approx 2 1/2 cups (I suggest 1/2 c. Gruyere shredded, 1/2 c. American cubed, 1 1/2 c. Cheddar shredded)
Onion finely chopped, about 1 Tablespoon
Garlic finely chopped, one medium clove
Olive Oil & Butter
Milk about 2 cups
Flour about 1/3 cup
to flavor the sauce: pinch of nutmeg, pinch of crushed red pepper, 2 tsp. Dijon mustard, salt & black pepper to taste.
to top: bread crumbs, Parmesan cheese, salt, and bits of butter.

First cook the pasta according to the manufacturers directions. Rinse well and set aside. Next you will need to prepare your cheeses, set aside and start the Roux (Roux is just a fancy word for the base of the sauce - made up mostly of flour and milk). First saute the onion and garlic over low heat with approx 2 tablespoons of olive oil and 1 tablespoon of butter. Once the onion is soft and transparent get out your whisk - now you will be going back and forth between adding a little flour then a little milk (whisking all the while) until you have about 1 - 1 1/2 cups of semi-thick white sauce - something about the consistence of heavy cream. When you have a moment (perhaps after an addition of milk, while you wait for the sauce to thicken) you can add your seasonings. The thing about flour is this... it will continue to thicken with heat...you will just need to add more milk or take it off the heat if you want it to stop thickening. To add the cheeses, remove the pot from the heat, throw in the cheese and stir to melt. You may not melt it all completely, and that is just fine. Add your cooked noodles and stir to coat. A little of the sauce should still pool up in the bottom of the pan, just a bit, and if this does not happen then your sauce is too thick: just add a bit more milk and stir. Pour the noodles and sauce into greased casserole dishes (you can use just one, but I like a higher bread crumb to noodle ratio, so I end up with one 9x13 dish plus a bread pan). Cover the noodles with parmesan cheese and bread crumbs. Dot with butter. Cover with foil. Put in an oven set to BROIL. Let the pasta heat through ( 5 - 7 minutes) remove foil and allow to brown nicely under the broiler. Keep an eye on it!! Serve while warm. Yum.