Make several cuts across the stringy parts and prick the chicken with the tip of the knife.
Cut the chicken into bite-sized pieces
Place the pieces into a bowl and add soy sauce, Sake, Salt, Pepper, Grated ginger root and garlic, Sesame oil.
Rub the seasoning into the chicken and let it sit in the fridge for 30 minutes allowing it to absorb the seasonings.
Add a beaten egg to the seasoned chicken a little at a time and stirr it in to coat the chicken evenly. This will help soften the karaage and retain the savory juices inside.
Add potato starch. Lightly toss to coat.
Heat the vegetable oil to a relatively low temperature. Place the chicken pieces into the oil. At about 160 degrees celcius small bubbles will form around the chicken. dont touch them until the batter firms up. Otherwise they will break apart. When the batter forms up, flip them over.
Lightly brown the pieces, remove and place onto a cooling rack. The remaining heat will cook the insides.
Heat the oil to about 180 degrees celcius on high heat. Then place the chicken into the oil again. Brown the chicken pieces evenly.
When the outside is crispy and the color is gold and brown remove the excess oil. And one by one place them on the cooling rack.
Serve with a dipping sauce made of soysauce, chilli oil and mirin.