MIX mustard, soy sauce, garlic and pepper. Pour over chicken in shallow dish; turn to evenly coat both sides of each wing. Refrigerate 1 hour to marinate.
BEAT eggs and water in shallow bowl. Place flour, then sesame seed on separate large sheets of waxed paper. Dip chicken in flour, then egg mixture, then sesame seed, turning to evenly coat each wing with each. Place on rimmed baking sheet; cover with waxed paper. Refrigerate 1 hour.
HEAT oil in large skillet to 375°F. Add chicken, in batches; cook 6 to 8 min. or until golden brown and done, turning after 4 min.