Preheat oven to 375 degrees. In a small bowl, combine butter, matcham ginger, garlic, and chives.
Thoroughly pat dry the thighs with a paper towel. Carefully loosen the skins, and spread the matcha butter mixture in between the skin and flesh. Spread any remaining butter over the skin.
Season both sides with salt and pepper.
Heat a cast-iron skillet on medium-high and drizzle some canola oil. Once hot, lay the thighs skin side down and let render, until the skin is slightly golden brown and crispy.
Lift the thighs and place lemon and onion slices on the bottom of the pan. Place the thighs on top and pour ¼ cup of chicken broth into the pan. Roast for about 20 to 25 minutes, or until the meat is cooked and the juices run clear.