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Potato and Leek Gratin

By Ashley Moore

Published on August 19, 2016

Time

1¾ hours

Yield

Serves 6 to 8

Potato and Leek Gratin

Ingredients

2 tablespoons unsalted butter 2 pounds leeks, white and light green parts only, quartered lengthwise, sliced ½ inch thick, and washed thoroughlySalt and pepper 4 garlic cloves, minced½ cup dry white wine 1 cup chicken broth ½ cup heavy cream 2 pounds large Yukon Gold potatoes, peeled and sliced ⅛ inch thick2 teaspoons minced fresh thyme 4 ounces Gruyère cheese, shredded (1 cup)

Before You Begin

Do not prepare the potatoes ahead of time or store them in water; the potato starch is essential for thickening the sauce. A mandoline makes quick work of slicing the potatoes.

Instructions

  1. Adjust oven rack to middle position and heat oven to 350 degrees. Grease 13 by 9-inch baking dish. Melt butter in 12-inch skillet over medium-high heat. Add leeks and 3/4 teaspoon salt and cook, stirring occasionally, until softened, 5 to 7 minutes. Add garlic and cook until fragrant, about 30 seconds; transfer to bowl.
  2. Return skillet to medium-high heat, add wine, and cook until nearly evaporated, about 2 minutes, scraping up any browned bits. Add broth and cream and bring to simmer; cook until slightly thickened and reduced to 1 1/4 cups, 3 to 5 minutes.
  3. Toss potatoes, thyme, 1 teaspoon salt, and 1/2 teaspoon pepper together in separate bowl. Spread half of leeks evenly in prepared dish. Arrange half of potatoes over leeks. Spread remaining leeks over potatoes. Arrange remaining potatoes evenly over leeks. Pour broth-cream mixture over potatoes and sprinkle with Gruyère.
  4. Bake until potatoes are tender and cheese is spotty brown, about 45 minutes. Let cool for 15 minutes. Serve.
Potato and Leek Gratin

Potato and Leek Gratin

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Time

1¾ hours

Yield

Serves 6 to 8

Ingredients

2 tablespoons unsalted butter
2 pounds leeks, white and light green parts only, quartered lengthwise, sliced ½ inch thick, and washed thoroughly
Salt and pepper
4 garlic cloves, minced
½ cup dry white wine
1 cup chicken broth
½ cup heavy cream
2 pounds large Yukon Gold potatoes, peeled and sliced ⅛ inch thick
2 teaspoons minced fresh thyme
4 ounces Gruyère cheese, shredded (1 cup)

Test Kitchen Techniques

Ingredients

2 tablespoons unsalted butter
2 pounds leeks, white and light green parts only, quartered lengthwise, sliced ½ inch thick, and washed thoroughly
Salt and pepper
4 garlic cloves, minced
½ cup dry white wine
1 cup chicken broth
½ cup heavy cream
2 pounds large Yukon Gold potatoes, peeled and sliced ⅛ inch thick
2 teaspoons minced fresh thyme
4 ounces Gruyère cheese, shredded (1 cup)

Test Kitchen Techniques

Ingredients

2 tablespoons unsalted butter
2 pounds leeks, white and light green parts only, quartered lengthwise, sliced ½ inch thick, and washed thoroughly
Salt and pepper
4 garlic cloves, minced
½ cup dry white wine
1 cup chicken broth
½ cup heavy cream
2 pounds large Yukon Gold potatoes, peeled and sliced ⅛ inch thick
2 teaspoons minced fresh thyme
4 ounces Gruyère cheese, shredded (1 cup)

Test Kitchen Techniques

Why This Recipe Works

For our potato and leek gratin, we needed to find a way to cook both vegetables until tender. But this didn’t mean finagling just the cooking time—we needed to find the right way to cut them, too. Cutting the leeks into 1/2-inch pieces ensured that there wouldn’t be slippery strips of leeks, and slicing the potatoes very thin—just 1/8 inch thick—ensured that they would be cooked through and tender in just 45 minutes. We jump-started the leeks in a skillet and cooked them down with some white wine for acidity.

Before You Begin

Do not prepare the potatoes ahead of time or store them in water; the potato starch is essential for thickening the sauce. A mandoline makes quick work of slicing the potatoes.

Instructions

  1. Adjust oven rack to middle position and heat oven to 350 degrees. Grease 13 by 9-inch baking dish. Melt butter in 12-inch skillet over medium-high heat. Add leeks and 3/4 teaspoon salt and cook, stirring occasionally, until softened, 5 to 7 minutes. Add garlic and cook until fragrant, about 30 seconds; transfer to bowl.
  2. Return skillet to medium-high heat, add wine, and cook until nearly evaporated, about 2 minutes, scraping up any browned bits. Add broth and cream and bring to simmer; cook until slightly thickened and reduced to 1 1/4 cups, 3 to 5 minutes.
  3. Toss potatoes, thyme, 1 teaspoon salt, and 1/2 teaspoon pepper together in separate bowl. Spread half of leeks evenly in prepared dish. Arrange half of potatoes over leeks. Spread remaining leeks over potatoes. Arrange remaining potatoes evenly over leeks. Pour broth-cream mixture over potatoes and sprinkle with Gruyère.
  4. Bake until potatoes are tender and cheese is spotty brown, about 45 minutes. Let cool for 15 minutes. Serve.

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