Preheat the oven to 450 degrees. \nHalve the sweet potatoes, lengthwise, then cut into ¾-inch thick chunks. Place on a parchment-lined baking sheet and toss with 1 tablespoon oil and 1 teaspoon kosher salt. Spread in a single layer and transfer to the oven. Roast, tossing once halfway through, until the potatoes are tender and beginning to brown, about 30-35 minutes. \nMeanwhile, whisk the mayonnaise with 2 tablespoons This Little Goat went to Tokyo sauce. Transfer sauce to a small Ziplock bag (this will act as a disposable squeeze bottle once you snip off the bottom corner). \nWhile still warm, gently toss the potatoes with the remaining 2 tablespoons Tokyo sauce. Transfer to a large serving bowl and toss with scallions and pepitas. Snip one bottom corner off of your Ziplock bag and drizzle Tokyo mayo all over the potatoes. Serve warm or at room temperature.