Combine the sliced chicken with soy sauce, cornstarch, sherry, and sugar; set aside. Cut broccoli flowerettes into 2-inch long pieces, taking care to slice pieces equal in size. Slice stalks into half-inch rounds.
Place 2 tablespoons oil in a wok over high heat. Add broccoli and salt. Stir- fry broccoli for about 2 minutes; remove from wok and transfer to plate.
Add remaining oil in wok and add onion slice. Stir onion over high heat several times and then add chicken mixture. Stir-fry constantly until chicken is almost cooked, about 2 minutes.
Return cooked broccoli to wok and combine with chicken mixture. Stir together until chicken is completely cooked through. Serve immediately with rice. Makes 4 servings.
