Step 1

Cut the chicken (skin, fat, and all) into 3/4 inch cubes. To a medium bowl or resealable plastic bag, add 1/3 cup each of soy sauce, mirin and sake, and two tablespoons ginger. Add the chicken, toss with the marinade, and refrigerate for a minimum of one hour but ideally three to 24 hours.

Step 2

In a small bowl, mix the remaining soy sauce and mirin, the wasabi, and the remaining ginger. Reserve for dipping.

Step 3

Preheat a deep fryer, or fill a tall, heavy, medium pot one-third full of oil. Heat the oil to 350F.

Step 4

While the oil is heating, drain off the chicken marinade. To a medium bowl, add the potato starch. Add the chicken a few pieces at a time and toss until each piece is well covered. Shake off the excess starch. Transfer the pieces to a drying rack or a plate and let rest for ten minutes.

Step 5

Divide the chicken into two batches and fry the first batch for three minutes, or until golden brown and crispy on the outside, and cooked throughout. Remove the chicken with a slotted spoon and drain on paper towels. Repeat with the second batch.

Step 6

Sprinkle with sesame seeds and green onion slices, and serve with the dipping sauce.