Preheat your oven to 400°F (200°C). Pat the chicken thighs very dry with paper towels to ensure crispy skin. Season both sides lightly with salt and black pepper.
In a small bowl, whisk together honey, soy sauce, rice vinegar, minced garlic, grated ginger, sesame oil, and red pepper flakes until smooth. Set aside.
Heat an oven-safe large skillet (cast iron preferred) over medium-high heat with a drizzle of neutral oil. Place the chicken thighs skin-side down and sear undisturbed for 5-6 minutes, until the skin is deep golden brown and crispy. Flip and sear the other side for 2 minutes.
Pour the prepared glaze over the chicken, spooning some onto the top of each thigh. Carefully transfer the skillet to the preheated oven. Bake for 20-25 minutes, or until the internal temperature of the thickest part (avoiding bone) reaches 165°F (74°C).
Remove from the oven and let the chicken rest in the skillet for 5 minutes. Sprinkle with sliced scallions and toasted sesame seeds before serving. Drizzle any remaining pan sauce over the top.