When you’re choosing which dishes to make ahead of time for Thanksgiving, these creamy mashed potatoes should be at the top of your list. A mixture of meltingly tender leeks cooked in butter and kissed with garlic is stirred into hot, just-riced potatoes along with sour cream and half-and-half.

Make-ahead Mashed Potatoes

Ingredients

• 3 pounds Yukon Gold potatoes, peeled and halved, or quartered if large
• 2 1/2 teaspoons kosher salt, divided, plus more for boiling
• 5 tablespoons unsalted butter, divided
• 1 leek, white and light green parts only, sliced into half-moons (about 1½ cups)
• 2 large cloves garlic, grated with a Microplane or minced
• 1 cup sour cream
• 1/2 cup half-and-half, warmed, plus more if reheating
• 1/2 teaspoon freshly ground black pepper, plus more for serving

Directions

Place potatoes in a large pot and cover with cold water by 1 inch. Generously salt water and bring to a boil. Reduce heat to medium-low; cook, stirring occasionally, until potatoes are very tender but not falling apart, 20 to 30 minutes. Drain. Press with a ricer and return to pot, or mash with a potato masher.

Meanwhile, melt ¼ cup of butter in a medium skillet over medium. Add leek and ½ teaspoon salt. Reduce heat to medium-low; cook, stirring occasionally, until leek is very tender, 10 to 15 minutes. Add garlic; cook, stirring constantly, until fragrant, about 1 minute.

Add sour cream, half-and-half, leek mixture, pepper, and remaining 2 teaspoons of salt to potatoes. Stir well to combine.

To serve immediately, transfer to a serving dish. Top with remaining 1 tablespoon butter and more pepper.

To Store and Prep at Feast Time

Refrigerate for up to 3 days. To serve, heat ½ cup half-and-half in a large pot over medium-low until warm, 2 to 4 minutes. Stir in potato mixture. Cover and cook, stirring occasionally, adding more half-and-half if needed, until warm, 10 to 15 minutes. Season with salt to taste.

Transfer to a serving dish and top with 1 tablespoon butter and more pepper.