1 tbsp mirin
3 garlic cloves , crushed
1 tbsp soy sauce
thumb-sized piece ginger , peeled and finely grated
8 boneless, skinless chicken thighs , cut into strips
100g potato starch
sunflower oil , for frying
4 large or 8 small soft burger rolls
2 Baby Gem lettuces , shredded
Mix together the mirin, garlic, soy and ginger to make a marinade. Mix 1 tbsp of this into the mayonnaise, then cover and chill. Put the chicken in a large bowl, pour over the remaining marinade and leave at room temperature for 10 mins, or longer in the fridge if you have time.
Spread the potato starch over a plate and roll the chicken pieces in it until coated. Heat 2cm oil in a large saucepan over a medium heat. Carefully add one-third of the chicken and fry for about 8 mins, turning occasionally, until crisp and cooked through. Lift from the oil, set aside on kitchen paper, then repeat with the rest of the chicken. Serve in the rolls with the mayonnaise and lettuce.