My Mom makes this with a ham dinner. I really don't like mac and cheese, but this I really enjoy. As far as I can recall, she used Paula Deen's Recipe. With the left overs, she cubes her ham up, and mixes it with the mac and cheese.
Boil the macaroni in a 2 quart saucepan in plenty of water until tender. Then drain your macaroni.
In a medium saucepan, mix butter and cheese. Stir until the cheese melts. In a slow cooker, combine cheese/butter mixture and add the sour cream, soup, salt, milk, mustard and pepper and stir well. Add eggs.
add drained macaroni and stir again. Set the slow cooker on low setting and cook for 3 hours, stirring occasionally.
Can be done in the oven.. 350 degrees for about an hour and a half.