In a medium saucepan, add the pasta, milk, mustard, garlic powder and nutmeg and turn on the heat on medium-high. Bring the milk to a simmer (just as you start seeing little bubbles form).
Quickly turn it down to LOW. You don’t want the milk to heat too fast and boil over into a mess!
Let the macaroni cook in the milk mixture over the low heat…stirring often. And by often, I mean often…every 30 seconds. It will take 6-8 minutes from this point for the pasta to soak up all the milk. You need to stir because the pasta on the bottom will absorb the liquid, and you don’t want the pasta on the top to be chewy. So it needs to be turned over. You’ll see what I mean when you try it! If you think it needs a little more liquid, add water 1/4 cup at a time. I didn’t need any…but you can if you need it. (This is cool to watch…and would be a great little “experiment” or cooking science lesson for kids.)
Once the pasta is al dente, remove it from the heat and stir in the shredded cheese and Parmesan cheese.
Serve immediately with favorite side dishes…fresh veggies or fruit!