In a large bowl, whisk together the hoisin sauce, honey, soy sauce, five-spice powder, minced garlic, and grated ginger until fully combined. Add the chicken thighs to the bowl, ensuring they are well coated in the marinade. Cover and let them marinate for at least 30 minutes at room temperature, or for deeper flavor, refrigerate for up to 4 hours.

Preheat your oven to 375°F (190°C) or prepare your grill for direct heat. If using an oven, line a baking sheet with parchment paper for easy cleanup.

Once marinated, place the chicken thighs skin-side up on the prepared baking sheet. Bake in the preheated oven for 25-30 minutes, or until the chicken is mostly cooked through and the internal temperature reaches 165°F (74°C). The marinade should caramelize slightly, giving a glossy appearance.

To add that signature Char Siu flavor, transfer the baking sheet to the grill and cook the chicken for an additional 2 minutes per side. Alternatively, broil in the oven for about 2-3 minutes, keeping a close eye to prevent burning.

Remove the chicken from the grill or oven and let it rest for a few minutes. Slice the thighs and serve hot, garnished with toasted sesame seeds and chopped green onions.