In a large bowl, toss chicken with rice vinegar, greens onions, ginger, soy sauce, 1/2 teaspoons salt, and 1/4 teaspoons pepper; chill 1/2 hour to 8 hours. Drain checken well; discard marinade. Dip chicken in crumbs OR Panko; shake off excess.
Heat 2 tbsps. oil in a non-stick skillet over medium-low heat. Cook 1/3 to 1/2 of the chicken without crowding until no longer pink in the center, about 2-3 minutes per side; drain on paper towels. Repeat until all chicken is used.