In a large bowl, combine honey, soy sauce, apple cider vinegar, olive oil, garlic powder, onion powder, black pepper, red pepper flakes, and salt. Whisk until well blended.
Add the chicken thighs to the marinade, ensuring they are fully coated. Cover and refrigerate for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill or a large skillet over medium-high heat.
Remove the chicken from the marinade, allowing excess marinade to drip off. Discard the remaining marinade.
Cook the chicken for about 6-7 minutes on each side, or until the internal temperature reaches 165°F and the chicken is nicely caramelized.
Remove the chicken from the heat and let it rest for 5 minutes before slicing.
Garnish with chopped green onions and serve warm.