Roasted Lamb with Celery Root, Potatoes, and Brussels Sprouts

Potato–Celery Root Gratin:

• 1 garlic clove
• 1 tablespoon unsalted butter
• 1 pound Yukon gold potatoes, peeled and thinly sliced
• Salt and fresh ground white pepper to taste
• Nutmeg to taste
• 1 celery root (about 1 pound), peeled and thinly sliced
• 2 pints heavy cream

Roasted Lamb:

• 2 eight-bone lamb racks, trimmed of fat
• Salt and freshly ground white pepper to taste
• 2 tablespoons olive oil

Brussels Sprouts

• 1 pound Brussels sprouts, tough outer leaves removed
• 1 tablespoon unsalted butter
• Grated zest from 1 lemon
• 1 teaspoon freshly squeezed lemon juice
• Salt and pepper to taste

To make the gratin, preheat the oven to 375ºF. Rub a 2-quart gratin dish with the garlic and then with butter.

Make a layer of potato slices in the bottom of the dish and season with salt, freshly ground white pepper, and grated nutmeg. Add a layer of celery root, season again, and press down. Add another layer of potatoes, season again, and press down on the potatoes. Continue building up the alternating layers until you reach the top of the dish, pressing down on each new layer. Pour the cream over the gratin, making sure the liquid just covers the surface. Bake for 2 hours, until the potatoes have softened and turned golden brown on top. Remove from the oven and tent with foil to keep warm.

To make the lamb, preheat the oven to 375°F. Generously season the lamb with salt and white pepper. Heat the olive oil in a large frying pan over high heat. Add the lamb racks and sear until well browned, about 3 to 5 minutes on each side.

Transfer the lamb to a roasting pan and roast for 10 to 15 minutes in the oven until medium rare (130ºF). Remove the lamb and let rest on a cutting board for 5 to 8 minutes.

To make the Brussels sprouts, fill a large pot with cold water, season generously with salt, and bring to a boil. Using a sharp paring knife, cut a deep cross into the base of each sprout. (This will help the centers cook without overcooking the outsides.) Add the Brussels sprouts to the boiling water, cover, and boil for 5 minutes, until just tender. Drain and transfer to a bowl. Toss the Brussels sprouts with the butter, lemon zest, lemon juice, and season with salt and black pepper.

To serve, slice the lamb racks into individual chops. Place a few chops on a plate and serve with some potato-celery root gratin and Brussels sprouts on the side.