Heat about 5 quarts of hot water in large pot with lid on. When water comes to a rolling boil, add about 1 tablespoon of salt and the entire box of pasta. Stir well, and continue to stir occasionally until pasta is almost completely cooked. I used shells, because that was what I had, but any small pasta would work well.
Preheat oven to 425 degrees.
Meanwhile, using your big bowl, combine milk, tomato sauce and cheeses. I used leftover spaghetti sauce because we had it, but jarred pasta sauce or plain canned tomato sauce works well too. Sprinkle in red pepper flakes to taste.
Drain cooked pasta well and add to bowl, stirring well to combine. Place mixture in 9x12 casserole dish sprayed well with cooking spray.
Dot the top of the macaroni and cheese with butter, and cook in preheated oven on a cooking sheet for about 30 minutes, or until bubbly and melted. Cool briefly and sprinkle basil on top.
Serve immediately or wrap with foil and refrigerate. Re-warm in a moderate 300 degree oven for about 15 minutes or until warmed through.