In a nonstick sauce pan cook the macaroni in salted water according to package directions, drain into a colander. No need to rinse.
In same pan melt the cheddar cheese and milk stirring often.
Stir in the macaroni and stir to coat well and heat just until hot again. Stir in the sour cream and salt. It will be somewhat thin, but thickens fast as it cools. Serve right out of the pan or put in a casserole and bake at 350 degrees until golden brown. Either way is the same, awesome!