Instructions:
- Combine chicken pieces with all marinade ingredients (ginger, garlic, salt, pepper, soy sauce, sake/mirin). Mix well, cover, and refrigerate for at least 1 hour.
- Prepare the dry mix by whisking together potato starch, flour, and baking powder in a large bowl.
- Gradually whisk ice-cold water into the dry mix until a slightly thick, shaggy batter forms. Do not overmix.
- Drain the marinated chicken briefly. Dredge thoroughly in the dry mix first, shaking off excess, then dip into the wet batter, ensuring complete coating. Place coated chicken on a plate.
- Heat frying oil in a deep pot to 325°F (160°C).
- First Fry: Fry the chicken in small, uncrowded batches for 6–8 minutes until lightly golden. Remove and drain immediately on a wire rack. Let rest for 10 minutes.
- Increase the oil temperature to 375°F (190°C).
- Second Fry: Return the rested chicken to the hot oil in batches. Fry aggressively for 2–3 minutes until deep golden brown and shatteringly crisp. Remove and drain again.
- Make Sauce: While chicken rests, simmer gochujang, honey/maple syrup, soy sauce, rice vinegar, garlic, ginger, and brown sugar in a small saucepan for 3–4 minutes until slightly thickened. Remove from heat and stir in the sesame oil.
- Transfer the hot, crispy chicken to a large bowl. Pour about two-thirds of the sauce over the chicken and toss quickly and thoroughly to coat evenly. Serve immediately.