Roasted Sweet Potatoes With Sesame-Soy Butter

Preparation

1. Step 1

   Place a rack in middle of oven and preheat to 400°. Place 2 lb. medium sweet potatoes (about 3), scrubbed, halved lengthwise, on a parchment-lined rimmed baking sheet; drizzle with 2 Tbsp. extra-virgin olive oil and sprinkle with 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt. Toss to coat. Arrange sweet potatoes, cut side down, and roast until easily pierced with a fork, 40–50 minutes.

   Step 2

   Meanwhile, heat ½ cup (1 stick) unsalted butter in a small saucepan over medium, stirring constantly, until it foams, then subsides and turns golden brown with small brown specks throughout, about 4 minutes. Immediately transfer to a medium heatproof bowl and whisk in 2 Tbsp. toasted white sesame seeds, 1 Tbsp. plus 1 tsp. toasted sesame oil, 1 Tbsp. soy sauce, 1 Tbsp. unsweetened cocoa powder, and 2 tsp. pure maple syrup. (Don’t worry if mixture is not completely smooth.) Chill cocoa-sesame butter until partly solidified (it should be mostly firm but scoopable), about 40 minutes.

   Step 3

   Cut 3 scallions, white and pale green parts only, crosswise into 2"–3" pieces. Cut each piece in half lengthwise, then in half lengthwise again, or thirds if larger, to create long, thin matchsticks. (You want to end up with pieces that are relatively similar in size, so if any scallions are particularly large, cut them in half again.) Transfer to a large bowl of ice water and let soak 10 minutes. Drain curled scallions, then pat dry with a kitchen towel or paper towels.

   Step 4

   Transfer sweet potatoes to a platter and arrange cut side up. Top each half with a generous dollop of cocoa-sesame butter and scatter scallions over.