1. Cut chicken crosswise on a diagonal into very thin slices. Cut zucchini crosswise into thin slices. Cut red pepper into thin 1 1/2 inch strips. Slice scallions.
2. In a small bowl, dissolve cornstarch in cold chicken broth. Stir in soy sauce and sherry. Set sauce aside.
3. Heat a wok or large non-stick skillet until hot. Add oil and heat until almost smoking. Add chicken and stir-fry, separating slices, 2 minutes. Add zucchini, red pepper, scallions, ginger and salt. Cook over high heat, tossing constantly, until chicken is white throughout and vegetables are crisp-tender, 2-3 minutes.
4. Stir reserved sauce and add to pan. Cool, stirring until sauce thickens and coats chicken and vegetables, 1-2 minutes. Serve it once.
