Macaroni and cheese gets a veggie update with butternut squash!
Melt 1 tablespoon of the butter in a medium saucepan over medium-low heat. Cook, stirring often, until the onions are very soft and turning brown, about 10-15 minutes. Remove to a plate.
Fill the now-empty pot 2/3 of the way with water. Bring to a boil. Generously salt the water. Add the pasta and cook according to the package instructions. Drain and return to the pan.
Add the remaining ingredients. Cover the pot and turn the heat to low. Let sit for 2 minutes. Remove the lid and give everything a good stir. Continue letting it sit covered, and then stirring until it forms a smooth sauce. Serve immediately. Garnish with parsley if desired. Serve with bacon to make it more of a main dish.