Preheat the oven to 375°F.
In a small bowl, mix together soy sauce, honey, sesame oil, red pepper flakes, minced garlic, and grated ginger.
Pat the chicken thighs dry, drizzle with 1 tablespoon of oil, and sprinkle with kosher salt, garlic powder, black pepper, and onion powder.
Heat a large, oven-safe sauté pan over medium-high heat. Add 2 tablespoons of oil and place chicken thighs skin-side down. Sear for 3 minutes until golden brown, then flip and cook for an additional 2 minutes.
Remove chicken from the pan and set aside. Pour the prepared sauce mixture into hot pan, scraping up any browned bits.
In a separate bowl, whisk together cornstarch and water until smooth. Add this mixture to the sauce in the pan and simmer until thickened.
Return chicken to the pan, coating it with the sauce. Bake in the oven for 30 minutes, basting every 10 minutes.
Remove chicken from oven, garnish with cilantro and green onions, then serve.