Step 1

Boil the macaroni in water for six minutes and drain.

Step 2

In a medium saucepan, mix butter and cheese. Heat over medium high heat and stir until the cheese melts.

Step 3

Spray your slow cooker with non-stick cooking spray. Combine cheese mixture, sour cream, soup, salt, milk, mustard and pepper in your slow cooker. Add the drained macaroni and stir again.

Step 4

Cook on low for 2 to 2 1/2 hours, stirring occasionally (I cooked mine for about 2 hours and stirred it twice and it was perfect).