Whisk miso paste, soy sauce, garlic, ginger, and sesame oil until smooth.
Pour marinade over chicken thighs and toss to coat. Marinate for at least 15 minutes, up to 1 hour.
Preheat oven to 400°F. Line a baking sheet with parchment paper or foil.
Arrange chicken thighs in a single layer on the sheet, leaving space between each piece.
Roast for 25–30 minutes until caramelized and fully cooked.
Let rest for 5 minutes after removing from oven.
Garnish with toasted sesame seeds and sliced scallions before serving.
Notes
Optional: Use pressure cooker for initial cook then finish under broiler for crispy edges. Store leftovers in fridge up to 3 days or freeze for up to 2 months.