01 - Preheat oven to 400°F. Position the rack in the center of the oven.
02 - In a large mixing bowl, combine grated ginger, minced garlic, tamari, honey, olive oil, rice vinegar, black pepper, sea salt, ground coriander, and red chili flakes. Whisk until thoroughly blended.
03 - Pat the chicken thighs dry with paper towels. Add them to the marinade and toss to coat evenly. Allow to marinate at room temperature for at least 15 minutes, or refrigerate up to 4 hours for more pronounced flavor.
04 - Scatter the sliced onions and lemon across the bottom of a 9x13-inch baking dish. Arrange the marinated chicken thighs skin-side up on top, pouring any remaining marinade over the chicken.
05 - Bake uncovered for 40–45 minutes until the skin is golden brown and the internal temperature reaches 165°F at the thickest part of the thigh.
06 - For an extra-crisp finish, switch the oven to broil on high for the final 2–3 minutes, watching carefully to prevent burning.
07 - Remove from the oven and let the chicken rest for 5 minutes. Garnish with freshly chopped cilantro or parsley before serving.