Make Ahead Mashed Potato Casserole

By kathya5084

This is great for Thanksgiving. It can be made 3 to 4 days in advance.

Ingredients

• Potato Ingredients
• 5 pounds russet potatoes, peeled and cut into 1 inch cubes
• 4 garlic cloves (optional)
• 2 shallots, minced (optional)
• Kosher salt - 2 teaspoons, one at a time and taste
• Freshly Ground pepper, to taste
• 1 1/2 stick butter (12 - tablespoons), cubed and slightly softened
• 1 cup (8 ounces) sour cream
• 3/4 to 1 cup warm heavy cream
• Topping
• 1 cup Panko bread crumbs
• 1 cup parmesan cheese
• 5 tablespoons butter

Preparation

Step 1

Preheat oven to 350°F.
Set cubed potatoes in a colander and rinse under cold water until water runs clear.
Transfer to a large saucepan, add garlic if using, and cover with cold water by at least 2 inches. Season water with salt until water is salty like tears. Bring water to a boil over high heat, then reduce heat to medium-low and simmer until a knife easily pierces potatoes with no resistance, 10 to 15 minutes. The potatoes should almost, but not totally, fall apart.
Drain potatoes in colander, then rinse with hot running water for 30 seconds.
Spread potatoes in an even layer on a large rimmed baking sheet and transfer to oven until excess moisture has evaporated and surface of potatoes is dry, about 6 minutes.

Potato Masher
If using a potato masher, transfer cooked potatoes to a large mixing bowl, add the 12 tablespoons softened butter, room temperature sour cream and mash until only very small lumps remain. Add the warm heavy cream and shallots, if using, and fold with a rubber spatula until fully incorporated. Season with salt to taste.
Transfer potatoes to a 9- by 13-inch or 3 quart baking dish and smooth surface.
Cover with plastic wrap and refrigerate for up to 4 days.

Ricer
If using a ricer, rice potatoes into a large mixing bowl, then fold in the 12 tablespoons softened butter, room temperature sour cream, warm heavy cream and shallots, if using, until fully incorporated. Season with salt to taste.
Transfer potatoes to a 9x13-inch or 3 quart baking dish and smooth surface.
Cover with plastic wrap and refrigerate for up to 4 days.

To Cook
One hour before cooking, remove potatoes from refrigerator and let stand for 1 hour.
Meanwhile, preheat oven to 350°F.
Scatter pieces of butter over the top and bake casserole until lightly browned and potatoes are heated through, about 50 to 60 minutes. If using a 3 qt deep casserole, test middle of casserole to see if hot. Add additional time, if necessary.
Mix Panko, parmesan and butter until topping is crumbly. Sprinkle evenly over the casserole and bake another 10 to 15 minutes until golden brown.