Buttery, Oniony, Charred Hash Browns

🥘 Ingredients

• russet potatoes, peeled and cut into 1- to 2-inch cubes 2 ½ lbs
• kosher salt
• unsalted butter 8 Tbsp
• olive oil 2 Tbsp
• large onions, thinly sliced 2
• freshly ground black pepper

1. 1

   Place the russet potatoes, peeled and cut into 1- to 2-inch cubes in a large saucepan and cover with cold water by 1 inch. Season generously with kosher salt . Bring to a boil over high heat and boil until the potatoes are completely tender but not falling apart, 8 to 10 minutes ; a cake tester or fork should pierce the potatoes with no effort. Drain the potatoes, transfer to a large bowl , and set aside.
2. 2

   Heat 4 tablespoons of the unsalted butter (divided) and the olive oil in a 12-inch heavy-bottomed nonstick or cast-iron skillet over medium-high heat until the butter melts. Add the large onions, thinly sliced and cook, stirring frequently, until softened and beginning to brown, 8 to 10 minutes . Using tongs or a slotted spoon , transfer the onions to the bowl with the potatoes, leaving the fat in the skillet. Fold the potatoes and onions together and season to taste with kosher salt and freshly ground black pepper .
3. 3

   Add 2 tablespoons butter to the skillet and heat over high heat, swirling until the foaming subsides and the butter starts to brown. Add the potato mixture to the skillet and press down with a silicone spatula until an even cake is formed. Reduce the heat to medium-high and cook, shaking the pan gently every minute or so, until the bottom is completely browned and verging on charred, about 5 minutes . Use the spatula to lift and flip the potatoes in sections, slicing and folding to incorporate the browned sections into the interior. Press the cake into the skillet again and repeat the browning and folding steps two or more times: you should end up with a potato cake that is riddled with crisp bits of potato and sweet onions.
4. 4

   Push the potatoes to one side, add the remaining 2 tablespoons butter, and melt it. Then lift the potatoes over the butter and spread and press into an even layer. Cook until the cake is completely crisp on the bottom, about 5 minutes , shaking the skillet every minute or so to prevent sticking. Remove the skillet from the heat and place an inverted large plate over the top. Carefully flip the potatoes out onto the plate, so that the crisp side is facing up, and serve (or keep warm in a low oven until ready to serve).