This is my favorite mashed potato recipe: wonderful as is, or as a base for the many embellishments and improvisations listed below. You can modulate their richness and texture according to whim or the ingredients you have on hand. I often use buttermilk to mash the potatoes instead of milk or cream because it has a natural creaminess yet is very low in fat, making them lighter, though no less addictive than your usual mashed potato (with a faint, delicious tang) welcome during a big feast like Thanksgiving.

Using part or all half-and-half or cream will make the potatoes denser and creamier.

I add butter at the end, after the potatoes have absorbed the liquid, so that it stays on the surface of the potatoes, its flavor readily discernible, imparting a truly buttery finish.

I like to use a finely textured, thin-skinned potatoes like Yellow Finns or Yukon Golds because they become extremely creamy when mashed.

Recipe: Buttermilk Mashed Potatoes

You can make the potatoes up to 3 hours ahead.  About 20  minutes before serving, warm them in a double boiler, stirring frequently, until they are hot.

Makes 3 cups, 4 servings; it can be scaled up indefinitely

1 1/4 pounds thin-skinned potato, such as Yellow Finns, Binje, German Butterball or Yukon golds, peeled

1 1/2 teaspoons salt or more to taste

About 3/4 cup buttermilk, milk, half-and-half or cream, in any combination, warmed

1 to 3 tablespoons unsalted butter, to taste

Freshly ground pepper to taste

Place the potatoes and 1 teaspoon of the salt in a medium saucepan; add enough cool water to cover. Bring to a boil over high heat. Reduce the heat to moderate and simmer until the potatoes are tender when pierced with a fork, about 45 minutes. Drain.

Return the potatoes to the pot and set in over low heat, uncovered for about 5 minutes, stirring occasionally, to let the potatoes dry out a little (too much moisture will dilute their flavor).

For the smoothest potatoes, pass them through a food mill. For a slightly coarser puree, mash them with a potato masher, fork or immersion blender. Beat the buttermilk and/or cream into the potatoes with a wooden spoon until thoroughly incorporated.  Stir in the butter a tablespoon at a time until you’ve got the level where you want it,  the remaining 1/2 teaspoon salt and plenty of freshly ground pepper to taste. Serve at once or keep the potatoes in a double boiler or bain marie over hot water for up to 1 hour.

Variations and Improvisations (to give you a few ideas)

Coarse-Mashed Potatoes with their Skins
Sometimes I’m in the mood for an earthier version of mashed potatoes, like those I loved as a child when I visited friends who lived on a farm in upstate New York. I use thin-skinned new potatoes or Yellow Finns. Tiny new potatoes such as fingerlings or rattes are also lovely and have delicious skins. Following the recipe above, cooking the potatoes in their skins (which should be well scrubbed) and coarsely mash them with a fork or hand masher, leaving lots of lumps.

Mashed Potatoes Seasoned with Olive Oil, Flavored Oils or Walnut Oil You can use other fats besides butter to flavor the potatoes. Pungent fruity extra virgin olive oil or Flavored Oils such as rosemary or Crispy Sage and Garlic Oil (below)  or white truffle oil are always delicious. In the south-west of France fine roasted walnut oil is often stirred in at the very last-minute for a surprising effect. I use 4 teaspoons oil for four servings, blending half into the potatoes and drizzling half on top.

Crispy Sage and Garlic Oil (1 scant up)
In a small heavy saucepan, combine 1 cup extra-virgin olive oil and the 5 garlic cloves, peeled and thinly sliced. Cook, covered, over moderately low heat, stirring frequently, until the garlic is just barely golden, about 5 minutes. Remove the garlic with a slotted spoon and drain on paper towels. Add 1/2 cup (lightly packed) fresh sage leaves (one 1/2-ounce bunch) and heat uncovered until tiny bubbles surround the leaves: frizzle until the leaves release their fragrance and darken somewhat. Cover and set aside to steep several hours. Strain into a clean dry jar, reserving the sage leaves. Drain them on paper towel with the garlic. Sprinkle lightly with sea salt to use as a garnish. The oil will keep indefinitely refrigerated.

Basil Mashed Potatoes
These fragrant delicately flavored, pale green potatoes go especially well with seafood, poultry, and lamb and veal.  In a mortar, pound 30 medium basil leaves with 1/4 teaspoon coarse salt, to a fine paste adding 1 tablespoon extra-virgin olive oil (instead of the butter in the original recipe). Alternatively you can make this puree in a blender to give it a finer texture. Stir the puree into the finished mashed potatoes

Roasted Garlic Mashed Potatoes.
These are profoundly earthy potatoes. Stir 1/4-1/2 cup Roasted Garlic Puree into Buttermilk Mashed Potatoes at the same time as the buttermilk.  Sometimes I add about 1 teaspoon ground coriander which I toast in a dry skillet until fragrant.

To make Roasted Garlic Puree (about 1 cup):
Preheat the oven to 400′. Gently peel of the papery white skin off the outside of about pound (4 large or 8 small heads) of garlic to reveal the cloves, without detaching them. Place them on a sheet of aluminum foil. Brush each head with olive oil and sprinkle with salt and pepper. Nestle fresh thyme sprigs among them. Dribble 2 tablespoons water onto the foil. Pull the ends of the foil up and crimp tightly together to form package. Place on a baking sheet.

Bake the garlic until the flesh is soft, about 35 minutes. With your fingers, queeze the soft puree out of the skins into a bowl or run the heads through a food mill. Stir in a few teaspons extra-virgin olive oil. Keeps at least a week in a clean dry jar in the fridge.

Smashed Potatoes with Crushed Black Olives
Follow the recipe for the Buttermilk Mashed Potatoes but mash the potatoes coarsely with a fork so that they are very lumpy. Instead of butter, drizzle them with 1 tablespoon fruity extra-virgin olive oil instead of butter. Add 1/2 cup pitted coarsely chopped or crushed black olives, such as Nicoise, Kalamata or Gaeta.

Horseradish Mashed Potatoes
Mashed potatoes are sensational prepared with fresh horseradish root, which is pungent and hot at the same time. The ugly gnarled root available at greengrocer has a distinct flavor that goes particularly well with roast beef and steaks and roast chicken. Prepared horseradish, which is preserved in vinegar,  produces an unpleasantly insipid version that is not worth the effort.

Peel a 2-inch chunk of fresh horseradish root. Grate as finely as possible. Stir 2 tablespoons or more to taste into Buttermilk Mashed Potatoes.

Wasabi Mashed Potatoes
Wasabi powder is ground dried Japanese horseradish that is made into a paste to accompany sushi; it has a biting, somewhat herbal flavor, and a surprising “heat” that creeps up slowly but can hit the nose in the same sinus clearing way as regular horseradish. Potatoes flavored with wasabi are wonderful with any Japanese style preparation like miso-glazed grilled fish.

In a small bowl, combine about 1 1/2 tablespoons wasabi powder with 1 1/2 tablespoons hot water (or the potato cooking water). Stir to a paste. Add 1 tablespoon to start, taste, then add more as desired. Stir this into Buttermilk Mashed Potatoes.

Sorrel Mashed Potatoes
Sorrel is the leafy herb available most often in the summer that has a tart lemony “green” flavor. You can often find it in the herb section of your grocery store. These potatoes are especially good with fish and poultry dishes.

Wash 3/4 pound fresh sorrel leaves in several changes of water and spin dry in a salad spinner. Chop the leaves coarsely. In a medium heavy saucepan, melt 1 teaspoon butter over moderate heat. Add the sorrel, cover, and cook, stirring frequently, until the sorrel has wilted. Uncover, reduce the heat to low and cook, stirring, until most of the watery juices have evaporated and the sorrel has “melted” into a thick puree. Stir in salt to taste. Remove from the heat and allow to cool slightly. Stir the sorrel puree into Buttermilk Mashed Potatoes.

 Mashed Potatoes Flavored with Pungent Aged Cheese
Any pungent hard aged cheese is delicious in potatoes: its flavor is so concentrated that a little goes a long way. Simply grate about 1/3 cup of any of the following: aged Gouda or Jack cheese, Spanish Manchego, Parmigiano Reggiano and aged goat cheeses like Crottin de Chavignol or Boucheron. Beat the cheese into the potatoes at the same time as the buttermilk.

Mashed Potatoes with Root Vegetables
I often substitute up to half the potatoes in the recipe above with root vegetables like parsnip, celery root, rutabaga and parsley root, either singly or in combination.  Peel the root vegetables and potatoes and cut them into 1-inch chunks.  Cook as directed above until tender reserving 3/4 cup of the cooking liquid.  Mash as directed using the reserved cooking liquid and heavy cream.

Milkless, Creamless, Butterless (Dairyless) Mashed Potatoes
These potatoes are for those souls who cannot have any dairy products. They are delicious. Boil the potatoes as directed in Buttermilk Mashed Potatoes.  You will not need the buttermilk or butter.  While the potatoes are cooking, add 2 tablespoons fruity extra-virgin olive oil, 1 small garlic clove thinly sliced and 2 teaspoons minced fresh rosemary or sage to a small skillet. Cover and cook slowly over low heat, until the garlic is translucent and just turning golden, and the herbs are very fragrant. Set aside

Drain the potatoes reserving 1 cup of the cooking liquid, and transfer them to a large bowl.  Mash with a potato masher or fork until fairly smooth or pass them through a food mill. With a wooden spoon beat in enough of the cooking water to make creamy puree. Then stir in 2 teaspoons of the oil, and salt and pepper to taste. Drizzle the rest of the oil over the top.