Pat duck legs dry with paper towels. Lightly score the skin in a crosshatch pattern without cutting into the meat. Season lightly with salt and a little black pepper.

Preheat a cast iron pan over medium-high heat. Once hot, place duck legs skin side down and sear until the skin turns golden and crispy, 6 to 8 minutes. Remove duck legs from the pan and set aside.

In a separate medium saucepan over medium heat, combine hoisin sauce, soy sauce or tamari sauce, honey, Chinese five spice, star anise, cumin, and onion powder. Add minced garlic, sliced ginger, and chopped scallions. Sauté together for 2-3 minutes until fragrant and the spices bloom.

Stir in the chopped kimchi and cook for another minute. Pour in the chicken stock and plum wine or rice wine, stirring to combine. Bring to a simmer, then remove from heat.

Preheat oven to 325°F (160°C). Pour the prepared sauce mixture into a braising dish or oven-safe pot. Nestle the seared duck legs into the liquid, skin side up.

Cover the dish and transfer to the preheated oven. Braise for about 75 minutes, until the meat is very tender and nearly falling off the bone.

Remove duck to a plate. Transfer the braising liquid to a saucepan and simmer over medium-high heat uncovered until glossy and thick enough to coat the back of a spoon, about 10 minutes. Taste and adjust to your preference.

Return duck to the sauce briefly to glaze. Serve with extra sauce spooned over and a shower of thinly sliced scallions.