Preheat the oven to 350°F and lightly grease a 2-quart casserole dish or large cast-iron skillet.
Bring a pot of water to a boil on high, add about a tablespoon of salt, then add the pasta. While occasionally stirring, cook per the package instructions until the pasta is tender. Remove the pot from the stove and drain the pasta.
Stir together the milk and corn starch. Return the pot the stove and pour in the milk and corn starch mixture. Turn the heat to medium low and while stirring, cook until the milk begins to thicken, about 2 minutes.
Turn the heat down to low and start adding the cheese to the pot, a handful at a time. Stir until the cheese melts then add the next handful. Once all the cheese has been added and melted, add the butter to the pot, along with the drained pasta. Taste and add salt if needed along with a few shakes of black pepper.
Stir until the pasta is well coated. The sauce will be thick, though if it feels too thick you may thin it with more milk.
Spoon the macaroni into the casserole. Cover then cook for 20 minutes or until the pasta is bubbling. Serve warm.
Macaroni and cheese, Texas cafeteria style | www.homesicktexan.com