Timing is everything when preparing multiple Thanksgiving sides, especially when the end goal is to serve them all at least warm.
If there is one dish that boils up a panic while inevitably creating a kitchen sink mess, it’s mashed potatoes.
A day-before prepped mashed potato casserole can be a game changer, guaranteeing fluffy, buttery, creamy results nestled under a savory golden crust. “My family loves mashed potatoes, but making the classic recipe is such a drag when cooking for a crowd,” says Jack Bishop, tasting lab expert for the PBS series “America’s Test Kitchen and Cook’s Country.” “Who wants to boil, mash or rice potatoes at the last minute?”
With all the mashing and mixing done a day beforehand, this potato casserole recipe is a perfect convenience dish during the holiday season. Another added point? It puts the ball back in your court in a hectic kitchen.
“I assemble this casserole on Wednesday so all the peeling, boiling, and mashing is done well in advance,” says Bishop, who celebrates and cooks Thanksgiving with his family at their home in Cutchogue, “the unbaked potatoes are fine in the ‘fridge for 24 hours.”
That factor alone can also help considerably with bring-a-dish requests at holiday potlucks, with simple instructions for popping in the oven for 35 minutes. The main ingredient should also be easy to grab while shopping for locally grown vegetables.
“Our 5 pound bag of russet potatoes will be available at our farmstand on Sagg Main the Wednesday before Thanksgiving,” says renowned farmer Marilee Foster of Fosters Farm, “and at the Sagaponack distillery, which gives customers the unique opportunity to drink and eat the same potatoes… theoretically.”
While this recipe creates a flavorful bite with the addition of Dijon mustard and fresh garlic, good-tasting potatoes will take it up a notch; packed in colorful bags with the Tiger Spuds logo and the “Grown on Long Island” stamp is also irresistible when you’re working to source your ingredients from as nearby as possible.
“The reason our potatoes taste different is because they are grown in soil well suited for a tuber that takes 100 plus days to mature,” explains Foster. “Sagaponack and Bridgehampton both share the namesake dirt, Bridgehampton loam,” says Foster of their farmland, recognized as grade A soil by both farmers and governmental agricultural agencies. “Add to that the maritime climate that potatoes thrive in; even when it’s dry and hot, our fields are cool and moist.”
Implementing an extensive cover crop program that rotates crops to avoid endemic pests and weeds, Foster and her brother Dean’s motto of “Don’t mess with it too much” is evident in the taste of their potatoes.
“Farming is a balance of mitigation and holding on,” says the sixth-generation farmer.
Balancing your time with family this Thanksgiving can also be implemented while preparing this new addition to your home cook repertoire, most efficiently after taking the turkey out of the oven and freeing up coveted oven space.
“While the bird rests, you can bake the potatoes,” instructs Bishop of this casserole recipe developed and perfected in 2008. “All those eggs help the potatoes souffle a bit as they bake and I love the crisp ridges on top (made with a fork before baking.) America’s Test Kitchen tip? Take the baking dish with the potatoes out of the fridge an hour before you bake them (so they are not icy cold), and then increase the baking time by about 10 minutes.
Allowing the dish to cool slightly on the counter will still achieve warm and comforting results and grant forgiveness if some of your other sides offered might have been side-lined.
Happy Thanksgiving!
Mashed Long Island Potato Casserole
Ingredients
- 4 lbs russet potatoes, peeled and cut into 1-inch chunks
- 1/2 cup half-and-half
- 1/2 cup low-sodium chicken broth
- 12 tbsp unsalted butter (1 1/2 sticks), cut into pieces
- 1 clove garlic, minced
- 2 tsp Dijon mustard
- 2 tsp salt
- 4 large eggs
- 1/4 cup finely chopped fresh chives
Directions
- Adjust oven rack to upper-middle position and heat oven to 375 degrees. Bring potatoes and water to cover by 1 inch to boil in large pot over high heat. Reduce heat to medium and simmer until potatoes are tender, about 20 minutes.
- Heat half-and-half, broth, butter, garlic, mustard, and salt in saucepan over medium-low heat until smooth, about 5 minutes. Keep warm.
- Drain potatoes and transfer to large bowl. With electric mixer on medium-low speed, beat potatoes, slowly adding half-and-half mixture, until smooth and creamy, about 1 minute. Scrape down bowl; beat in eggs 1 at a time until incorporated, about 1 minute. Fold in chives.
- Transfer potato mixture to greased 3-quart baking dish. Bake until potatoes rise and begin to brown, about 35 minutes. Let cool 10 minutes.
Make ahead:
- The baking dish with the potatoes can be covered with plastic and refrigerated for up to 24 hours.
- When ready to bake, let the casserole sit at room temperature for 1 hour. Increase baking time by 10 minutes.
* Recipe courtesy of America’s Test Kitchen. You can find thousands more kitchen-tested recipes on their website and app.
