Create the marinade by combining mochiko, cornstarch, sugar, soy sauce, eggs and green onions in a medium bowl. Make sure everything is blended. Cut chicken into bite-size pieces like nuggets, getting them as close to uniform in size as possible so they'll cook evenly when deep-frying.
Add chicken to the marinade and use your hands to massage the chicken pieces and make sure they're all coated by the marinade. Cover and refrigerate for at least 6 hours or up to overnight.
Bring oil to 350 degrees F in a deep-fryer or Dutch oven.
Fry chicken in batches until crispy, about 10 minutes. Sprinkle sesame seeds over the top, if using, and serve.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.