In a skillet, heat oil over medium-high. Brown meat on all sides. Add broth; cover and simmer until beef is tender, about 1 hour. Add cauliflower, green pepper, soy sauce, garlic, and ginger root if desired. Cover and simmer until the vegetables are tender, about 5-7 minutes. Combine cornstarch, sugar and water. Stir into meat mixture. Bring to a boil, stirring constantly; cook 2 minutes or until thickened. Stir in green onions. Serve on rice.