FRENCH ONION DOMINO POTATOES ARE CRISPY, CRUNCHY, CHEESY, AND PRACTICALLY PERFECT

French Onion Domino Potatoes Are Crispy, Crunchy, Cheesy, and Practically Perfect image

This shingled sheets of thinly sliced potatoes are crispy on the outside, tender on the inside, and topped all over with deeply caramelized onions and melty cheese.

Provided by @MakeItYours

Number Of Ingredients 7

Ingredients

2 pounds medium russet potatoes (about 4)
5 tablespoons olive oil or clarified butter, divided
1 1/4 teaspoons kosher salt, divided
2 medium yellow onions (about 1 1/2 pounds total)
1 cup shredded Gruyère cheese (about 4 ounces)
1/4 cup dry sherry
1 tablespoon unsalted butter

Steps:

Arrange a rack in the middle of the oven and heat the oven to 400°F. Line a rimmed baking sheet with parchment paper.
Trim the ends from 2 pounds medium russet potatoes. Trim all 4 long sides of each potato so that each potato is shaped like a brick without any skin. Using a mandoline, cut the potatoes lengthwise into 1/6-inch-thick slices, being careful as you glide the potato across the blade, not only of your fingers but also applying enough pressure to ensure an even slice.
Place the potato slices in a large bowl. Drizzle with 3 tablespoons of the olive oil or clarified butter and season with 1/2 teaspoon of the kosher salt. Toss well to coat the slices evenly with the oil and salt.
Position the baking sheet with a longer side closer to you. Arrange the potato slices across the baking sheet in 3 rows: For each row, shingle 1/3 of the slices (15 to 18), overlapping each slice by 1/2-inch. Drizzle the potatoes with any remaining olive oil left in the bowl.
Bake until the potatoes are golden-brown with crispy edges and knife tender, about 40 minutes. Meanwhile, cook the onions.
Halve 2 medium yellow onions and thinly slice with the grain (about 6 cups). Heat the remaining 2 tablespoons olive oil in a 10-inch skillet over medium heat until shimmering. Add the onions and remaining 3/4 teaspoon kosher salt and cook, stirring often, until the onions are beginning to soften, about 9 minutes.
Reduce the heat to low and continue cooking, stirring often, until the onions are deep golden-brown, 30 to 35 minutes more. Meanwhile, grate 4 ounces Gruyère cheese on the large holes of a box grater if needed (1 cup).
Add 1/4 cup dry sherry and 1 tablespoon unsalted butter to the onions. Cook, stirring frequently, until the mixture is the consistency of marmalade, about 1 minute.
When the potatoes are ready, remove the baking sheet from the oven. Increase the oven temperature to 500°F.
Spread the onion marmalade evenly over the shingled potatoes and sprinkle with the cheese. Return the baking sheet to the oven and bake until the cheese is melted and bubbly, about 5 minutes. Let cool for 5 minutes before using kitchen shears or a sharp knife to cut into squares.