If you’re like me, you look at the above photo and think, hmm what in the world is this? With fall/winter produce in the markets, comes some new discoveries in the kitchen. I bought this bumpy looking root vegetable and came home determined to find it a good recipe. The bit of fresh growth at the top of the root gives away the name of this ingredient…

Celery root, also known as celeriac, has a knobby exterior that is best peeled very carefully with a paring knife. The best way to store celery root is in the fridge, unpeeled, in an unsealed plastic bag, with a dry paper towel to absorb excess moisture. If you store it this way it will stay fresh for up to 3 weeks!

Thanksgiving is coming up and I’ve made so many gratin recipes that I’m getting a little bored of them all. But, that’s where this recipe comes in. The combination of a new (to us) root vegetable, the buttery sautéed leeks and the twist of fresh thyme leaves make this dish a real winner. I can’t wait to make it for our Thanksgiving feast back home with my parents this year. The celery root has a subtle celery, duh!, odor that gives the gratin a nice zip and you can definitely detect the thyme leaves and leeks which give the dish an earthy and flavorful boost. I hope you’ll give this recipe a whirl. You can make it earlier in the day and reheat it while your turkey rests on the counter.

Potato and Celery Root Gratin with Leeks

Recipe From: Bon Appetit, November 2011

Makes: 4 to 6 servings

Ingredients:

• 1 1/2 cups heavy cream
• 2 garlic cloves, peeled
• 1 sprig thyme plus 2 teaspoons fresh thyme leaves, divided
• 1  1/2 Tbsp. unsalted butter
• 1 leek, white and pale-green parts only, halved lengthwise, thinly sliced crosswise
• Kosher salt
• 1 pound russet potatoes, peeled, very thinly sliced crosswise (1/8″ thick)
• 1/2 pound celery root, peeled, very thinly sliced crosswise (1/8″ thick)
• 1 cup grated Gruyère
• Freshly ground black pepper

Directions:

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.
2. Melt 1 tablespoon butter in a medium skillet over medium heat. Add leek; season with salt and cook, stirring often, until tender (do not brown), about 8 minutes. Transfer to a small bowl and set aside.
3. Butter a 3-quart gratin dish with remaining 1/2 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 all layers twice more.
4. Strain cream mixture into a medium pitcher and pour over vegetables.
5. 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.

MAKE AHEAD TIP: This recipe can be made 2 hours ahead. Let stand at room temperature. Tent with foil and rewarm in a 300°F oven until hot, about 20 minutes.