Ingredients:

5 pounds russet potatoes, peeled and cut into 3/4-inch cubes

kosher salt

1 stick (1/2 cup) unsalted butter, cubed and slightly softened

1 cup (8 ounces) sour cream (see note above)

1 cup heavy cream /whipping cream

6 thin slices bacon, diced

1 1/2 cups panko bread crumbs

1/4 cup thinly sliced scallions /spring onions, white and light green parts only

6 ounces grated cheddar cheese

Directions:

1. Preheat oven to 350°F. Set cubed potatoes in colander and rinse under cold water until water runs clear.

2. Transfer to a large saucepan and cover with cold water by at least 2 inches. Season water with salt.

3. Bring water to a boil over high heat, then reduce heat to medium-low and simmer until a knife easy pierces potatoes with no resistance, 10 to 15 minutes.

4. Drain potatoes in colander, then rinse with hot running water for 30 seconds. Spread potatoes in an even layer on 2 rimmed baking sheets and transfer to oven until excess moisture has evaporated and surface of potatoes is dry, about 6 minutes.

5. If using a potato masher, transfer cooked potatoes to a large mixing bowl, add butter and sour cream, and mash until only very small lumps remains then add heavy cream and fold with a rubber spatula until fully incorporated. Season with salt.

6. Transfer potatoes to a 9by 12-inch baking dish and smooth surface. Cover with plastic and refrigerate for up to 5 days. 2 hours before serving, remove potatoes from refrigerator and let stand for 1 hour.

7. Preheat oven to 350°F. In a saucepan, cook bacon over medium-high heat until fat has rendered and bacon is browned and crispy, about 6 minutes. Add panko to a large mixing bowl and scrape bacon and its rendered fat into it.

8. Stir well to combine. Stir in scallions and cheese and season with salt. Spread bread crumb topping on potatoes.

9. Bake casserole until topping is browned and potatoes are heated through, about 45 minutes. Serve.

Bon Appetit!