Hello All,
We make our Mac and cheese in house:
Make a roux and bechamel, mix in your cheese and seasoning, the simplist say salt and garlic and rosemary, then mix in the elbow mac? You can fridge  this and reheat in the microwave since the bachamel will prevent the cheese sauce from breaking.
You can brown some bacon or pancetta, or put some bread crumbs topping for textural (spelling) interest.
We top all our mac and cheese with some coney chili and it is indeed to die for.
WAy way way better than mac and cheese from a box.
 
Love,
SuperDog from Portland Oregon