This recipe takes inspiration from a dish called ‘Chicken Nanban’ where fried chicken is soaked in slightly acidic brine and served with rich egg 'tamago' tartare. Shuko's version uses Koya's favourite chicken karaage as a base, and is topped with Koya's own Fukujinzuke, a ginger pickled daikon.
Start by cutting your chicken into bite-sized pieces and marinate it in the karaage brine for 20 minutes.
While the chicken marinates, soft-boil an egg (7 minutes from boiling), then cool, peel and gently break it up with the back of a spoon. Mix with finely minced spring onion, mayonnaise, a squeeze of lemon juice and a pinch of salt, then set aside.
Make the Nanban brine by mixing soy sauce, rice vinegar, mirin and sugar until the sugar has dissolved. Set aside.
After the chicken has been marinating for 20 minutes, discard most of the karaage brine, leaving just a little behind to help coat it with half of the katakuriko. Add most of the katakuriko to the wet chicken and mix so the starch combines with the remaining brine, forming a light, sticky coating on the chicken.
Coat the chicken again with the remaining katakuriko to create a crispier outer layer. Fry the chicken in two stages: first for 4 minutes at 170°C, then rest for 5 minutes. Fry again for 2 minutes at 190°C until golden and crisp. While still hot, quickly toss the chicken in the Nanban brine.
Toast and butter your bun, then build the sandwich with a handful of salad leaves, the Nanban chicken, the egg tartare, and finish with a spoonful of Fukujinzuke on top.