Yukon Gold & Sweet Potato Gratin

Yukon Gold & Sweet Potato Gratin for a Crowd

1 clove garlic

3 tablespoons butter, plus 1 tablespoon for greasing your serving dish

1 quart heavy cream

1-2 teaspoons salt

freshly ground black pepper to taste

2 teaspoons finely chopped rosemary

2 teaspoons finely chopped sage

4-5 pounds Yukon Gold potatoes, peeled and sliced 1/8-1/4 inch thick on a mandolin

4-5 pounds sweet potatoes, peeled and sliced 1/8-1/4 inch thick on a mandolin

2 cups grated gruyere cheese

We cooked our gratin in a large baking dish on the show (a little larger than a 13 X 9 pan). This will feed a crowd. You can reduce the amounts of ingredient (or add a little more) to accommodate your family’s baking dish and appetites.

Preheat your oven to 350˚F degrees.

Take your garlic clove and rub it along the bottoms and sides of your baking dish. Spray the dish with nonstick cooking oil or rub with 1 tablespoon of butter to coat the sides and bottom.

Combine the heavy cream in a small pot with the remaining butter, salt, a pinch of black pepper and fresh herbs. Bring to a simmer and allow to reduce and marry the flavors for about 15 minutes.

Starting with the Yukon Gold potatoes, begin layering the slices in your baking dish, slightly overlapping the potatoes as you go. Once you complete one layer, repeat the process shingling the other direction with the sweet potatoes. Continue layering your potatoes, alternating ever layer, until you’ve filled your dish. As you layer, gently press on the potatoes to make sure they are settled in the dish as snuggly as possible.

Once you’re done layering, taste your cream mixture and add more salt and pepper if desired. Give the mixture a stir and pour into your baking dish until the cream comes about ¼ of the way up your potatoes. Cover the top with the grated cheese.

Spray a sheet of aluminum foil with nonstick cooking spray and cover the potato gratin. Place on a baking sheet and bake for about an hour. A knife tip should easily pierce the potatoes. Remove the aluminum foil and broil the gratin until the cheese is bubbling and golden brown. Carefully remove from the oven and let sit for at least 10 minutes before serving.