Step 1

Bring 2 quarts (2L) of water to a boil in a large saucepan or Dutch oven.

Step 2

Preheat the oven to 450ºF and arrange a rack in the bottom of the oven.

Step 3

While the water comes to a boil, prep the potatoes:Peel all the potatoes, including the Russet. Rinse the potatoes.Cut the Yukon Gold potatoes crosswise, then again lengthwise so you have quarters. They should be about 1 ½” pieces, no larger than 2" (4 to 5 cm) (see Note 1).For the Russet, slice lengthwise into quarters, then slice crosswise as thinly as you can.

Step 4

Once the water is boiling, add 2 tablespoons (20g) kosher salt and the potatoes. Cover to quickly bring back a boil, then uncover and reduce the heat to maintain a gentle simmer. Simmer uncovered for about 8 minutes, or until the centers of the Yukon Golds have softened and they offer a little resistance when pierced with a knife (Russets should be very soft and almost falling apart).

Step 5

While the potatoes simmer, transfer a medium roasting pan (11”x15” or 12”x16” or 30x40 cm) to the bottom rack of the oven. Preheat the pan for 10 to 15 minutes. If you don’t have a roasting pan, use a rimmed sheet pan.

Step 6

When the potatoes are done cooking, drain them. Return them to their hot pan to dry out for a few minutes.

Step 7

Transfer all the potatoes to a large bowl. Toss the potatoes vigorously for about 1 minute, or until a starchy coating starts to form on them, taking special care to mash up any Russet pieces with a fork.Pour in the olive oil, 1 ¾ teaspoons kosher salt, and a generous amount of black pepper. Use a silicone spatula to toss repeatedly until the starchy coating is even thicker, almost like mashed potatoes.

Step 8

Using oven mitts, remove the hot pan from the oven. Carefully add the potatoes into the pan (for the best texture, add the potatoes one by one to the pan). Use a small spatula to spread any excess mashed potato in the bowl onto the potatoes, trying to not let it fall onto the pan. Spread the potatoes out in a single layer with minimal touching.

Step 9

Roast for 20 minutes, then remove the pan. Use tongs to flip the potatoes. Roast for another 20 minutes, or until potatoes are nicely golden brown.Optional if using rosemary: While the potatoes roast, add the finely chopped rosemary to a small bowl and add just enough olive oil to make a thick, spoonable paste, ~ 1 scant tablespoon.

Step 10

After the 40 minutes, flip the potatoes again.If not using rosemary: return the potatoes to the oven and roast for 7 minutes, or until potatoes are deeply golden brown and crisp.If using rosemary: Scootch the potatoes close to one another and spoon the rosemary paste on top of them. Use a small spatula or spoon to spread out the rosemary as best you can. Spread out again. Roast for 7 minutes, or until potatoes are deeply golden brown and crispy.

Step 11

Remove from the oven, allow to cool for a few minutes, then enjoy. Taste, adding a pinch of fine sea salt as desired.