Most Thanksgiving leftovers have a certain fate. Turkey: club sandwiches. Cranberry sauce: peanut butter sandwiches. Stuffing: waffle iron. Pie: breakfast!

But the destiny of mashed potatoes is far less of a sure thing. At the holiday table, they are the golden child of sides: buttery and salty, cozy and humble. Fast-forward to Friday and they are all but unrecognizable; they are cold and depressed and lacking in hope. Enter: these recipes, all of which reinvigorate basic mashed potatoes with a fresh sense of purpose. My base included whole milk, butter, and salt, plus a bee sting of garlic. If yours is richer, say with cream or cheese, you’re one step ahead.

KALE SAMOSAS

Samosas are deep-fried, potato-filled pastries that originated in India and other South Asian countries. They are typically triangle-shaped, studded with green peas, and served with a sweet tamarind sauce. Here, I avoid the headache that is frying and call in flaky pie pastry instead. Use your go-to recipe, be it butter-, lard-, or shortening-based. All work equally well. The result yields all the indulgence with half the effort. While samosas are traditionally small and enjoyed as a street snack, these are personal-size. Add in a crunchy salad and you have dinner.

1 tablespoon unsalted butter
2 cloves garlic, peeled and minced
1-inch piece of ginger, peeled and minced
1 1/2 teaspoons cumin seeds
1 large poblano (or 2 small), chopped
1 1/2 cups chopped kale
1 cup frozen peas, thawed
2 cups leftover mashed potatoes
Salt to taste
Pie dough for 1 crust, divided in 4

Melt the butter in a medium skillet over medium heat. Add the garlic and ginger and sauté until soft and fragrant. Add the cumin seeds and stir for a minute or so to toast. Add the poblano and cook until soft. Add the kale and cook until it just starts to wilt. Add the peas and potatoes and stir to combine. Salt to taste. Let cool completely.

Preheat the oven to 375 degrees F. Form each pie-dough portion into a small disk. Roll each into a circle, about 7 inches in diameter. Divide the potato mixture evenly among the circles. Fold each in half and crimp shut. (Two reliable methods: Pleat the edges, like an empanada or dumpling, with your fingers, or seal with a fork.) Transfer the samosas to a parchment-lined sheet tray. Bake for about 25 minutes, rotating halfway through, until the crust is very colorful. Serve warm. Yield: 4 samosas

WHOLE-WHEAT PIEROGIES WITH CARAMELIZED ONIONS AND SOUR CREAM

Mash up Italian ravioli with Indian samosas and you get Polish pierogies. Many would argue they’re the best of the three, but let’s not argue when we could eat. These simple potato dumplings are boiled in salty water, like pasta, then pan-fried in butter, or not. You can serve them with sauerkrautthe collard rendition from Farmer’s Daughter would be wonderful hereor with sweet caramelized onions and sour cream. If you’d like a lighter alternative to the latter, swap in Greek yogurt.

1/2 cup whole-wheat flour
1/2 cup all-purpose flour
Pinch salt
1/2 cup just-boiled water (you may not use all of it)
1 tablespoon unsalted butter, plus more to finish
1 large yellow onion, chopped
Salt to taste
1 cup leftover mashed potatoes
Sour cream to garnish

Combine the flours and salt in a medium bowl. Add most of the water and stir until a cohesive, but not sticky, dough forms. If it seems too dry, add more water, bit by bit. Knead the dough on a clean work surface until smooth. Cover with a damp paper towel and let rest for a few minutes.

Meanwhile, melt the butter in a medium skillet over medium heat. Add the onions. Salt to taste. Let cook leisurely and lazily until they are very soft, very brown, very sweet. Lower the heat as needed and stir often.

Set a large pot of salted water on another burner over medium-high heat.

Divide the dough into 16 equal portions. Roll each into a small circle, about 3 1/2 inches in diameter. Add a tablespoon of mashed potato to each circle, then fold and seal into half-moons. Boil the pierogies in batches, cooking each for about 5 minutes. Pan-fry in butter until the edges begin to crisp. Drape with the caramelized onions and dollop with sour cream. Yield: 16 pierogies

BUCKWHEAT LEFSE

Lefse is less than approachable. Many recipes will warn that you need a “lefse griddle” and a “lefse stick” to ensure lefse success, as a scare tactic. But I promise all you need is a well-seasoned cast-iron skillet and a lot of butter, both of which we have plenty around here. This Scandanavian, potato-based, crepe-like flatbread can be served savory, with butter and salt, or sweet, with butter and sugar. In either case, butterand don’t forget it. I most like lefse topped with a runny, sunny egg, plus a thunderstorm of chives. If you have any extras, repurpose it into “tortillas” for tacos.

1 1/2 cups mashed potatoes
1/2 cup buckwheat flour
1/2 cup all-purpose flour
Butter to fry and to finish
Salt to finish

Mix the potatoes and flour together in a large bowlfirst by spoon, then by hand, until a smooth dough forms. Divide into 8 equal portions. Meanwhile, heat a cast-iron skillet over medium-high heat. Roll each dough ball into a circle, about 7 inches in diameter. Add a bit of butter to the pan and fry one lefse a time, cooking for 1 to 2 minutes per side until the outside is blistered. Sprinkle with salt and serve warm with butter to pass around. Yield: 8 lefse

FORAGER’S PIE

The classic Irish shepherd’s pie is a ground lamb casserole, polka-dotted with vegetables, covered by a mashed potato roof. The more American-friendly alternative, cottage pie, features ground beef. Though a vegetarian by no means, I prefer to forgo the meat altogether and opt for earthy mushrooms. You can use any varietybutton, cremini, shiitake, oyster, hen of the woodsbut ideally, mix and match a few different types to diversify flavors and textures. If any pie-eaters avoid gluten, substitute 2 tablespoons of cornstarch for the flour.

2 tablespoons unsalted butter
3 carrots, peeled and chopped
3 celery stalks, chopped
1 yellow onion, chopped
Salt to taste
20 ounces mushrooms, chopped
1 cup frozen peas, thawed
1 cup frozen corn, thawed
3 tablespoons all-purpose flour
1 cup vegetable stock
2 teaspoons Worcestershire
2 cups leftover mashed potatoes

Butter an 8-by-8-inch casserole dish. Melt the butter in a large skillet over medium-high heat. Add the carrots, celery, and onion, and sauté until soft. Salt to taste. Add the mushrooms and continue to cook until soft. Add the peas and corn and stir to combine. Add the flour and stir again. Slowly add the stock, stirring as you pour. Cook until the liquid just begins to thicken. Add the Worcestershire and season again with salt to taste.

Preheat the oven on the broiler setting. Transfer the mushroom mixture to the prepared casserole dish. Spread the mashed potatoes evenly over top. Slide under the broiler and bake until the top begins to crisp and brown. Let set for a few minutes before serving. Yield: 8-by-8-inch casserole