I am not a fan of macaroni and cheese, but can easily imagine a cold rainy night when this would be a great treat. I cut the recipe in half and it made too much. So tried it with 1/4 of the amounts. I added parmesan and chipotle powder to the cheddar. Warming. Wouldn’t mind a few dehydrated vegetables in there, either.
This hint came from Cate’s World Kitchen.

2 cups dried pasta (Cate used bow tied pasta)
2 cups 2% milk
1 cup loosely packed shredded cheddar cheese
1 tsp salt
1 tsp dijon mustard

Combine the pasta and milk in a saucepan and bring to a simmer. Cook, stirring, with the heat low for about 20 minutes (until the pasta is soft). Make sure the milk doesn’t boil! (I boiled water, added pasta and salt, then ,  after pasta was almost done, I added all the rest , powdered milk and mustard. Didn’t want to watch boiling milk.)
Stir in the mustard, salt, and cheese.
Cover and let stand for about 5 minutes, then stir well to serve.