Learn the basics of sauces from a French cooking book/course.

Make a blonde roux, for 4 pounds of cheese, add 1.5 cups of milk and 2 cups of half and half. Add in the shredded cheese saving about a pound to a pound and a half for layering. Add 4 tsp of sodium citrate. Voila you have a cheese sauce that won’t break on you that pours into the pasta easily.

God thank you I am so fucking frustrated by how much every fucking person in America has some idiotic combination of cheese and noodles and sometimes fucking eggs??! Which they combine and bake for an hour to make a terrible, dry, bland casserole which everyone insists is anything other than inedible slop like some weird collective delusion, when the real answer is literally just to do a thing from the first fucking week of French cooking lessons.