CHEESY POTATOES GRATIN

Cheesy Potatoes Gratin image

Provided by Anne Burrell

Time 2h5m

Yield 8 to 10 servings

Number Of Ingredients 10

8 tablespoons (1 stick) unsalted butter
1/2 yellow onion, finely diced
Kosher salt
2 cloves garlic, smashed and finely chopped
1/2 cup all-purpose flour
1 quart milk
1/4 cup Dijon mustard
2 cups grated Gruyere
1 cup grated Parmigiano
3 pounds Yukon gold potatoes, unpeeled, cut into 1/4-inch slices

Steps:

Preheat the oven to 375 degrees F.
Melt the butter in a large saucepan over medium heat. Add the onions, then season with salt and cook until the onions are soft and very aromatic, 5 to 7 minutes. Add the garlic and cook for another 2 to 3 minutes. Whisk in the flour and cook until the roux is the consistency of wet sand, 3 to 4 minutes. Whisk in the milk, bring to a boil and cook for 5 to 6 minutes. Turn off the heat and whisk in the mustard and cheeses. Season with salt to taste to make sure it is delicious!
Place a quarter of the potatoes in the bottom of a 9-by-13-inch baking dish. Ladle a quarter of the cheese sauce evenly over the potatoes. Repeat this process 3 or 4 more times with the remaining potatoes and sauce, pushing down the potatoes between each layer and topping with the sauce. Place the baking dish on a sheet tray lined with foil. Bake, rotating the dish halfway through, until the potatoes are soft when poked with a fork, 50 to 60 minutes. Tent with foil if the top is getting too brown.
Let sit for 15 to 20 minutes before serving.
Hot cheesy potatoes!