Why This Recipe Works: Mashed potato casseroles transform the humble potato into a comfort-food side dish that’s more than the sum of its parts. We wanted to design our smooth, cheesy, crunchy-topped casserole so it could be made ahead and reheated for company without fuss.
Keeping the potatoes creamy required mixing them with a dairy product. Whole milk and butter were obvious additions that loosened the mash to the right consistency but weren’t enough to prevent dry, grainy potatoes after reheating. Sour cream added luxury that lasted and a refreshing tang. The cheddar cheese didn’t incorporate well when we stirred it into the mash, so we sprinkled a cheesy layer on top. And, to complete the dish, we sprinkled a homemade breadcrumb topping over the cheese.
