Set a wire rack in a rimmed baking pan, or just use the baking pan. Remove chicken from marinade. One at a time, take a piece of chicken, dip into egg whites to coat, letting excess drip back into dish; then put into flour mixture to coat, while pressing firmly so the flour sticks to the chicken. Repeat for each piece. Transfer chicken to prepared wire-racked baking sheet pan and refrigerate, uncovered, for at least 30 minutes or up to 2 hours.