Name: Potato & Celery Root Gratin with Leeks
Yield: Makes 8 to 10 servings
Ingredients: 3 cups heavy cream; 2 garlic cloves, peeled; 1 sprig thyme plus 3 teaspoons fresh thyme leaves, divided; 2 tablespoons (1/4 stick) unsalted butter, divided; 3 leeks, white and pale-green parts only, halved lengthwise, thinly sliced crosswise; Kosher salt; 2 pounds russet potatoes, peeled, very thinly sliced crosswise (1/8" thick); 1 pound celery root, peeled, very thinly sliced crosswise (1/8" thick); 2 cups grated Gruyère; Freshly ground black pepper

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Potato & Celery Root Gratin with LeeksChristopher Testani

Celery root, also known as celeriac, has a knobby exterior that is best peeled (carefully!) with a paring knife.

Recipe information

Yield
Makes 8 to 10 servings

Ingredients

3 cups heavy cream

2 garlic cloves, peeled

1 sprig thyme plus 3 teaspoons fresh thyme leaves, divided

2 tablespoons (1/4 stick) unsalted butter, divided

3 leeks, white and pale-green parts only, halved lengthwise, thinly sliced crosswise

Kosher salt

2 pounds russet potatoes, peeled, very thinly sliced crosswise (1/8" thick)

1 pound celery root, peeled, very thinly sliced crosswise (1/8" thick)

2 cups grated Gruyère

Freshly ground black pepper

Preparation

Step 1
Preheat oven to 350°F. Heat cream, garlic, and thyme sprig in a medium saucepan just until bubbles begin to form around edge of pan. Remove from heat; set aside to steep.
Step 2
Melt 1 tablespoon butter in a medium skillet over medium heat. Add leeks; season with salt and cook, stirring often, until tender (do not brown), 10-12 minutes. Transfer to a small bowl and set aside.
Step 3
Butter a 3-quart gratin dish with remaining 1 tablespoon butter. Layer 1/3 of potato slices and 1/3 of celery root slices evenly over bottom of baking dish. Cover with 1/3 of leeks, then 1/3 of Gruyère. Sprinkle with salt, pepper, and 1 teaspoon thyme leaves. Repeat layers twice more. Strain cream mixture into a medium pitcher and pour over vegetables.
Step 4
Set gratin dish on a large rimmed baking sheet and cover tightly with foil. Bake for 1 hour. Carefully remove foil; continue baking until top is golden brown and sauce is bubbling, 25-30 minutes. DO AHEAD: Can be made 2 hours ahead. Let stand at room temperature. Tent with foil and rewarm in a 300° oven until hot, about 20 minutes.

TagsGratin Leek Root Vegetable Vegetable Russet Potato Potato Celery Root Gruyère Cheese Dairy Side Dinner Gluten Free Nut Free Vegetarian Oven Bake Bon Appétit

Recipe notes

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