Place potatoes in a large pot and cover with cold water by 2 inches. Add 1 tablespoon kosher salt. Bring to a boil over high heat, then reduce to a simmer and cook until a paring knife slides through easily, about 15 to 18 minutes depending on size. Drain well and let steam dry for 5 minutes. The drier they are, the crispier they get.

Preheat oven to 450 degrees F. Drizzle 2 tablespoons olive oil on a rimmed baking sheet. Arrange potatoes on the sheet, leaving space between them. Use a potato masher or the bottom of a heavy cup to gently smash each potato to about 0.5 inch thick. Some will break apart; that is fine. Drizzle remaining 1 tablespoon olive oil over the tops and roast until deeply golden and crisp at the edges, 20 to 25 minutes. No need to flip them.

While potatoes roast, whisk together chili crisp, rice vinegar, soy sauce, sesame oil, and honey in a small bowl until emulsified. Taste and adjust: add more vinegar for brightness, honey to tame heat, or soy for salt.

Transfer hot potatoes to a large bowl. Pour dressing over and toss gently to coat; the potatoes will absorb flavor as they cool slightly. Let sit 5 minutes, then toss again. Transfer to a serving platter, scatter with scallions and sesame seeds, and drizzle with more chili crisp if desired. Serve warm or at room temperature.