Make the marinade: In a large bowl or container, combine the white miso paste, gochujang, sesame oil, honey, minced garlic, and the white parts of the green onions. Mix well until smooth.
Marinate the chicken: Add the chicken thighs and coat evenly with the marinade. Cover and marinate in the fridge for at least 30 minutes, but overnight is best for deeper flavor.
To air fry: Preheat your air fryer to 380°F (193°C).
Place the chicken thighs skin-side up in a single layer in the air fryer basket.
Cook for 25–30 minutes, flipping halfway through, or until the internal temperature reaches 165°F (74°C) and the skin is crispy.
To bake: Preheat your oven to 400°F (200°C).
Place the chicken thighs on a parchment-lined baking tray or in a cast iron skillet, skin-side up.
Bake for 35–40 minutes, or until golden brown and cooked through (internal temp 165°F/74°C). Broil for 2–3 minutes at the end to crisp the skin.
Garnish and serve: Sprinkle the reserved green onion tops over the chicken before serving. Enjoy with rice, noodles, or your favorite veggies.