Prep the chicken: Pat the chicken very dry with paper towels. In a bowl, combine salt, pepper, ginger, garlic, soy sauce, and rice wine. Toss chicken to coat and let sit 20–30 minutes at room temperature.

Make the sauce: In a small saucepan, combine gochujang, ketchup, honey, brown sugar, soy sauce, rice vinegar, garlic, sesame oil, red pepper flakes (if using), and water. Simmer over low heat for 3–4 minutes until glossy and slightly thickened. Turn off heat and set aside.

Heat the oil: Fill a heavy pot with oil to about 2 inches depth. Heat to 325°F (165°C). Use a thermometer for accuracy.

Mix the batter: In a large bowl, whisk potato starch, flour, baking powder, and salt. Add cold water and the egg (if using). Stir just until combined; it should be loose, like thin pancake batter. Don’t overmix.

Coat the chicken: Add chicken to the batter, tossing to coat evenly. The thin batter helps build those crispy ridges.

First fry (cook through): Fry chicken in batches at 325°F for 5–7 minutes for wings or small thigh pieces. Don’t crowd the pot. Transfer to a wire rack set over a sheet pan. The chicken should be pale golden and cooked through.

Rest and raise the heat: Let the chicken rest 5 minutes. Increase oil temperature to 375°F (190°C).

Second fry (make it shatter-crisp): Fry the chicken again for 1–2 minutes until deep golden and super crispy. Move pieces around so they don’t stick. Return to the rack to drain.

Sauce and toss: Warm the sauce briefly if it’s thickened too much. In a large bowl, toss half the chicken with just enough sauce to lightly coat. Keep the other half unsauced if you like it extra crunchy. Sprinkle with sesame seeds and scallions.

Serve: Plate immediately with pickled radish, cold beer, or sparkling water. The contrast is part of the experience.