Note: To vary this dish, add broccoli florets or bok choi, coarsely chopped. In a wok or heavy skillet, heat the oil. Add ginger, garlic, onions, green pepper and celery; saute several minutes, stirring, until tender-crisp. Remove vegetables. (Can be done up to this point in advance, if desired.) Combine stock, soy sauce, sugar, salt and cornstarch in a small bowl; set aside. Heat skillet, adding more oil if needed. Add beef and sear quickly, stirring frequently, several minutes. Add stock-soy sauce mixture and cook, stirring constantly, until thickened. Add reserved cooked vegetables. Add quartered tomatoes and heat through. Serve with hot cooked rice. From _Nancy Enright's Canadian Herb Cookbook_ by Nancy Enright. Toronto: James Lorimer & Company, 1985. Pg. 55. ISBN 0-88862-788-2. Electronic format by Cathy Harned.