This spicy stir-fry has an Asian flavor and can be served with rice.
Cut chicken into thin strips, 2 1/2 to 3 inches long. In a medium bowl, whisk together egg white, cornstarch, 1 teaspoon coarse salt, and 1/4 teaspoon ground pepper until smooth. Add chicken strips, and toss to coat.
Heat 1 tablespoon vegetable oil in a large nonstick skillet over medium-high heat. Add half of coated chicken strips to skillet; cook, turning once, until golden, about 5 minutes. Transfer to a plate. Add another tablespoon vegetable oil to skillet, and brown remaining chicken in same manner.
Add celery, ginger, and jalapeno to remaining oil in skillet (add additional oil, if necessary); cook, tossing, until celery is crisp-tender, 4 to 5 minutes.
Stir vinegar, sesame oil, and sugar in with vegetables. Add scallions and cooked chicken; toss, until combined and heated through, 1 to 2 minutes. Serve immediately.
Bunches of celery can be kept in a plastic bag in the refrigerator for up to 3 weeks. Rinse before using.