Celeriac Potato Gratin

celeriac-chard-potato-gratin

Feel the coming winter chill? Now's the perfect time to get snuggly with your cheesemonger. Ask for a strong flavored, hard, aged sheeps' cheese such as a pecorino. The name percorino refers to the sheep (or 'pecora') whose milk is used to make this family of Italian cheeses. Lots of us have tried Pecorino Romano, but other sheeps' milk cheeses can be equally interesting. Our suggestion? Try manchego, Fiore Sardo from Sardinia, or Pecorino Ginepro, which is rubbed with balsamic vinegar and juniper berries. Celeriac is a nubby, rough-looking root vegetable. The best celeriac comes with its green stems and leaves still attached. It should be hard as a rock and heavy for its size. This recipe is a solid side dish that’s great for a holiday crowd.

Serves 8

 
  • 1clove garlic, cut in half
  • 2tablespoons unsalted butter, softened
  • 2large shallots, thinly sliced
  • 5large chard or beet leaves, stems removed, leaves cut in thin ribbons
  • 12cup (1 ounce) finely grated hard cheese
  • 2bulbs celeriac, peeled (1.5 pounds)
  • 2large yellow-fleshed potatoes, peeled (1.5 pounds)
  • 12teaspoon fine sea salt
  • 1tablespoon roughly chopped fresh thyme leaves
  • 1teaspoon finely grated lemon zest
  • 1cup heavy cream
    1
  • Heat the oven to 350 degrees. Rub the cut edge of the garlic around the inside of a 9x12-inch casserole dish. Brush the dish generously with butter, coating it completely.
  • 2
  • In a medium bowl, toss the shallots, chard leaves, and half of the cheese together, then set aside. Use a mandolin or a very sharp knife to cut the celeriac and potatoes into 18-inch thin slices.
  • 3
  • Lay down alternating slices of celeriac and potato in the bottom of the casserole dish, repeating until there are two layers. Sprinkle lightly with the sea salt, thyme, and lemon zest. Spread the chard mixture and then layer again with the remaining celeriac and potato. Pour in heavy cream. Sprinkle the top with remaining cheese.
  • 4
  • Place the casserole on a sheet pan with sides. Cover with a tent of foil, making sure the foil is not touching the top of the cheese. Bake for 1 hour, until the root vegetables are cooked through. Remove from oven and remove tinfoil. Turn the heat up to broil. Broil gratin until cheese is golden on top, about 2 minutes depending on your broiler. Let cool for 10 minutes before serving.