01 -
Set oven to 425°F and position rack in the center.
02 -
In a medium bowl, whisk together maple syrup, white miso, rice vinegar, and soy sauce until smooth. Stir in the water until fully incorporated.
03 -
In a large bowl, toss sweet potato rounds with 1 tablespoon of neutral oil and 1/2 teaspoon kosher salt until evenly coated.
04 -
Heat the remaining 1 tablespoon oil in a large oven-safe skillet over medium-high heat. Arrange sweet potatoes cut-side down and sear without moving until golden brown, about 2 to 3 minutes.
05 -
Turn sweet potatoes to sear the opposite side, sprinkle with the remaining kosher salt, and cook until golden, about 1 to 2 minutes more.
06 -
Add butter to the skillet and allow it to melt. Slightly tilt the pan and spoon melted butter over the potatoes several times until fragrant.
07 -
Pour the maple-miso mixture into the skillet until sauce comes halfway up the sides of the potatoes. Bring to a gentle simmer.
08 -
Transfer skillet to oven. Roast for 23 to 28 minutes, or until sweet potatoes are tender and sauce is slightly thickened.
09 -
Arrange sweet potatoes on a serving platter. Whisk the sauce in skillet, drizzle over potatoes, and sprinkle with flaky sea salt if desired.