Combine melted cheese, eggs, sour cream, soup, cream, milk, mustard, and salt and pepper in a slow cooker. Stir in the macaroni and give the entire mixture a couple stirs.
3 large eggs, ½ cup light sour cream, 10.75 oz. condensed cheddar cheese soup, ½ cup heavy cream, ½ cup milk, ½ tsp dry mustard powder, kosher salt and freshly ground black pepper