Sure, regular mashed potatoes are tasty. But with a couple of extra steps, you can turn them into something even more delicious — mashed potato casserole! I must admit that another motivation for making this dish was to use a vintage casserole dish from my collection. Corning Ware is a particularly handy choice, because you can assemble the casserole ahead, refrigerate it overnight, then pop it in the oven with no risk of thermal-shock-induced breakage.
3 lbs Yukon Gold potatoes, peeled and cut into 1-inch chunks
8 tbsp unsalted butter
3/4 cup sour cream
1/4 cup milk
1/2 tsp garlic powder
1/2 tsp salt
3 green onions, chopped fine
1 1/2 cups shredded Cheddar cheese
1/4 cup bread crumbs
Preheat oven to 375 degrees. Lightly grease a 1 1/2-quart baking dish with butter or cooking spray.
In a large pot, combine potatoes with enough water to cover. Bring to a boil, then cook until softened, about 15 minutes.
Drain the potatoes, then put back in the pot. Add 7 tbsp butter, cut into smallish pieces. Mash with a potato masher until butter has melted and is mixed in. Add sour cream, milk, garlic powder and salt and mash until smooth. Stir in green onions and 1 cup of the Cheddar.
Transfer the potato mixture to the prepared baking dish and spread evenly. (At this point the casserole can be covered and refrigerated overnight, if desired. Leave out at room temperature for 30 minutes before baking, and extend cooking time as needed.)
Melt 1 tbsp butter. In a small bowl, combine with bread crumbs and stir until butter is evenly incorporated. Stir in 1/2 cup Cheddar, then sprinkle the mixture over the potatoes.
Bake, uncovered, until topping is lightly browned, about 15-20 minutes.
Pictured: Corning Ware April DC-1 1/2-B Designer Casserole