Prep the chicken. Pat the chicken dry. In a bowl, combine the chicken with salt, pepper, soy sauce, and rice wine. Mix well and let sit for 10–15 minutes.
If using, stir in the egg white.
Coat for crunch. Add potato starch to a shallow bowl. Dredge chicken pieces, pressing to coat thoroughly. Shake off excess.
Set on a rack for 5–10 minutes so the starch hydrates slightly.
Heat the oil. Pour 1–1.5 inches of oil into a deep skillet or pot. Heat to 325–340°F (165–170°C). Keep a steady medium heat.
First fry. Fry chicken in batches without crowding, 4–5 minutes until lightly golden and cooked through.
Transfer to a rack. Let the oil return to temperature between batches.
Make the glaze. In a small pan, combine soy sauce, honey, rice vinegar, garlic, ginger, gochujang or flakes (if using), water, and sesame oil. For a thicker sauce, whisk in cornstarch before heating.
Simmer over medium heat 2–3 minutes until glossy and slightly thick.
Second fry for extra crisp. Increase oil to 360–375°F (182–190°C). Fry the chicken again for 1–2 minutes until deep golden and ultra crispy. Drain on a rack.
Sauce and toss. Add the hot chicken to a large bowl.
Pour over the glaze and toss quickly until every piece is coated and shiny.
Finish and serve. Sprinkle with sesame seeds, green onions, and nuts if you like. Serve right away with rice, pickled radish, or a cold beer.