Step 1

In a large saucepan, combine the potatoes, 6 cups water and 1 tablespoon salt. Bring to a boil over medium-­high and cook, stirring occasionally, until the potatoes are tender-crisp, 3 to 4 minutes. Drain the potatoes in a colander and rinse with cold water until cool to the touch. Toss the potatoes and shake the colander to remove as much water as possible, then pat dry with paper towels.

Step 2

In a medium bowl, toss together the potatoes, vinegar, sesame oil and sugar. Pile the scallion whites on top of the mixture but do not stir them in. Set a fine-mesh strainer across the bowl.

Step 3

In an 8-inch skillet over medium, heat the grapeseed oil, Sichuan peppercorns, árbol chilies and paprika (if using), stirring, until fragrant and the peppercorns begin to pop, 1 to 2 minutes. Immediately pour the mixture into the strainer over the scallion whites and potatoes; discard the solids in the strainer.

Step 4

Add the fresh chili to the potato mixture and toss. Taste and season with salt, then transfer to a serving dish. Top with the scallion greens and cilantro.