Method:

Dissolve cornstarch in sherry, oyster sauce, water, and add red pepper flakes. In wok or large skillet, heat oil over med high heat, add ginger and garlic. Stir−fry 1 min. Add broccoli, stir−fry 3 mins. Add green pepper, celery, and green onions, stir−fry 3 mins. Make a well in wok and add cornstarch mixture. Stir until thickened. Add meat and gently stir. 

Use chicken broth if mixture is too thick. Serve with steamed rice.