Step 1

Cook the macaroni noodles in a large pot of salted water according to package directions, draining them a minute before the "al dente" cooking time.

Step 2

Heat the milk in the microwave or on the stove top until very hot but not boiling.

Step 3

In a heavy bottomed sauce pot, melt the butter over medium heat. Whisk in the flour and continue to cook, whisking constantly, until the mixture turns a light brown color, about 3-4 minutes. Remove from heat.

Step 4

Slowly start pouring in the milk, whisking constantly. The mixture will look very thick at first and will thin out as you whisk in the remainder of the milk.

Step 5

Return the pot to the heat and cook the mixture, whisking continuously, another 3-5 minutes or until thickened. The sauce should coat the back of the spoon. If you put a little bit on a spoon and run your finger through it, the line from your finger should remain. Stir in the salt, garlic powder, ground mustard and cayenne (if desired). Season to taste with salt and pepper.

Step 6

Return the remaining sauce to the stove. Over low heat, add the cheeses, stirring to melt. If you're unable to melt in all the cheese, add a bit more milk, a Tablespoon at a time, until the cheese is melted completely. Stir the sauce into the pasta until your desired level of creaminess is reached. I find I use all of the sauce sometimes and sometimes I have a little leftover. Serve the pasta hot with a sprinkle of parsley if desired.