Measure the amount of onion and cube the cheese. (I had a bigger bag of noodles so I measured out 1 cup.)
Cook the macaroni, drain, and rinse.
Combine the mushroom soup, milk, onion, and seasonings. Mix until well combined.
Alternate layers of macaroni, soup, and cheese in a greased baking dish. Bake for about 45 minutes at 350 degrees. Stir halfway through.
Let it cool for a few minutes and enjoy!