2 cups uncooked elbow macaroni
4 tablespoons butter
2 1/2 cups grated sharp cheddar cheese
1/2 cup sour cream
1 (10 3/4 ounce) can condensed cheddar cheese soup
1/2 teaspoon salt
1 cup whole milk
1/2 teaspoon dry mustard
1/2 teaspoon black pepper

Boil the macaroni in water for six minutes. Drain.

In a medium saucepan, mix butter and cheese. Stir until the cheese melts.

In slow cooker, combine cheese mixture and add the sour cream, soup, salt, milk, mustard and pepper. Add the drained macaroni and stir again.

Cook on low for 2 1/2 hours, stirring occasionally.