Prepare the Thighs: Thoroughly pat the chicken thighs dry using paper towels. This step is critical for achieving a good sear. Season both sides of the thighs generously with the kosher salt and black pepper. Set aside.

Mix the Sauce Base: In a medium bowl, combine the soy sauce, honey, water (or broth), minced garlic, grated ginger (if using), and apple cider vinegar. Whisk these ingredients together until the honey has fully dissolved and the mixture is uniform.

Create the Slurry: In a small separate bowl, whisk the 1 tablespoon of cornstarch with 2 tablespoons of cold water until a smooth, thin paste (known as a slurry) is formed. This will be used later to thicken the sauce. Set the slurry aside.

Marinate (Optional but Recommended): Pour about half of the honey garlic sauce mixture over the seasoned chicken thighs in a large zip-top bag or shallow dish. Toss to coat completely. Allow the chicken to marinate at room temperature for at least 20 minutes, or refrigerate for up to 4 hours. Keep the remaining half of the sauce mixture separate, as this will be the final cooking sauce.

Heat the Pan: Heat the olive oil or vegetable oil in a large, heavy-bottomed skillet over medium-high heat until the oil is shimmering.

Sear the Chicken: Carefully place the marinated chicken thighs into the hot pan, ensuring they are not overcrowded (you may need to work in batches). Reserve any remaining marinade from the bag, as it can be added to the sauce later.

Cook for Color: Sear the chicken thighs for 5 to 7 minutes on the first side until deep golden brown and slightly caramelized. Flip the chicken and reduce the heat slightly to medium.

Finish Cooking: Continue to cook the chicken on the second side for another 5 to 8 minutes, or until the internal temperature reaches 165°F (74°C). Once cooked, remove the chicken from the skillet and transfer it to a plate. Cover loosely with foil to keep warm.

Bring Sauce to a Simmer: Pour the reserved half of the honey garlic sauce (the sauce that was not used for marinating) into the skillet. Bring the sauce to a rolling simmer over medium heat, scraping up any browned bits (fond) from the bottom of the pan using a wooden spoon.

Thicken the Glaze: Whisk the prepared cornstarch slurry one more time to recombine, then slowly pour it into the simmering sauce. Stir constantly for about 1 to 2 minutes. The sauce will rapidly thicken into a glossy, sticky glaze.

Glaze the Chicken: Return the cooked chicken thighs back into the skillet. Toss the chicken gently in the thickened sauce, turning them several times until they are completely coated and glossy with the honey garlic glaze.

Serve: Remove the chicken and sauce from the heat immediately. Garnish generously with fresh chopped parsley or green onions before serving. Serve hot over rice, noodles, or with steamed vegetables.