In a mixing bowl, whisk together the maple syrup, soy sauce, minced garlic, minced ginger, red chili flakes, apple cider vinegar, salt, and pepper until well combined.
Place the chicken thighs in a resealable plastic bag or a shallow dish and pour the marinade over the chicken. Seal the bag or cover the dish, then refrigerate for at least 1 hour, or overnight for more intense flavor.
Preheat your oven to 375°F (190°C).
In a large oven-safe skillet, heat the olive oil over medium heat. Remove the chicken from the marinade (reserve the marinade) and add it to the skillet. Sear the chicken for about 4-5 minutes on each side until golden brown.
Pour the reserved marinade over the chicken thighs and transfer the skillet to the preheated oven. Bake for 20-25 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (75°C).
Remove the skillet from the oven and let the chicken rest for 5 minutes before slicing.
Garnish with chopped green onions and sesame seeds before serving.
Notes
Serve with steamed jasmine rice and sautéed greens for a complete meal.