Crock Pot Mac and Cheese

I've made mac and cheese a bunch of different ways, but this is probably my favorite.  It's really easy, quick and can feed a crowd.  I served it as a side for Thanksgiving and we were pretty disappointed that we didn't have much of it leftover the next day.  It's easy to double the recipe, which I'll have to keep in mind next time!

Crock Pot Mac and Cheese
adapted from Paula Deen

2 cups elbow macaroni
4 tbsp butter
2 1/2 cups shredded cheddar
1/2 cup sour cream
1 can cheddar cheese soup
1 cup whole milk
1/2 tsp salt
1/2 tsp dry mustard
1/2 tsp black pepper

Boil macaroni for 6 minutes.  Drain.  In a medium sauce pan, (I use the same one) mix butter and cheese and stir until cheese melts.  In a slow cooker, combine cheese mix, sour cream, soup, salt, milk, mustard and pepper.  Add macaroni.  Mix together.  Set slow cooker to low for 2 1/2 hours.