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Robert St. John

Restaurateur, author, enthusiastic traveler, & world-class eater.

Potato Gratin

Potatoes are the one vegetable I could never give up. Fried, roasted, mashed, or scalloped—doesn’t matter, they’re always on the table in one form or another. This gratin is my favorite way to make them feel a little more special. It’s rich, creamy, and just decadent enough to make it feel like you’re putting in some extra effort. There’s a good bit of cheese in this recipe, but that’s exactly how it should be. The combination of sharp white Cheddar, gruyere, and Parmesan gives it the perfect balance of nuttiness, creaminess, and tang. And using Yukon gold potatoes instead of russets makes a big difference. They have just the right amount of starch to get creamy without getting mushy. This dish is a showstopper on the holiday table, but I’d eat it on a random Tuesday without hesitation.

Ingredients

2 tablespoons unsalted butter plus a little to butter the baking dish and parchment paper
1 small yellow onion, halved and very thinly sliced, about 1 cup
2 teaspoons fresh garlic, minced
1 teaspoon kosher salt
2 teaspoons vegetable seasoning (see recipe page ***)
2 cups Bechamel sauce (see recipe page ***)
1 cup heavy whipping cream
4 ounces sharp white Cheddar cheese, shredded, about 1 cup
4 ounces Gruyere cheese, shredded, about 1 cup
1/2 cup Parmesan cheese, grated
3 1/2 pounds Yukon gold potatoes, washed and patted dry

Instructions

Serves 8 to 10

Preheat oven to 375° F.

In a large skillet over medium heat, melt the butter. Stir in the sliced onion and sauté for four to five minutes, until the onions have wilted. Stir in the garlic, salt, and vegetable seasoning, and continue cooking for one minute.

Whisk in the Bechamel sauce and heavy cream and bring to a boil. Remove from the heat and stir in the white Cheddar, Gruyere, and half of the Parmesan. Hold the sauce warm while slicing the potatoes.

Lightly butter a 9×13 casserole dish. Using a mandolin or very sharp knife, slice the potatoes into 1/4-inch circles.

Spread a thin layer of the sauce on the base of the casserole dish. Shingle a layer of potatoes atop the sauce. Add another layer of sauce, spreading evenly to coat the potatoes. Continue this process, making sure to reserve enough sauce for the top layer.

Sprinkle the top with the remaining Parmesan cheese.

Cut a piece of parchment paper large enough to cover the surface of the casserole dish. Lightly butter the side to be placed on the potatoes. Secure the parchment by wrapping the dish in aluminum foil. Pierce the surface of the foil four to five times with a sharp knife.

Place the casserole on the center rack of the oven and bake for 35 minutes. Remove the foil and continue cooking for 15 to 20 minutes, until the potatoes are fork-tender.

Remove from the oven and let rest for 20 minutes before serving.

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