Cut meat into 1/2 inch squares. Brown meat in canola oil about 5 minutes.
Separate cauliflower into florets (about 4 cups). Add cauliflower, green pepper, soy sauce, and garlic. Stir lightly to coat vegetables with soy sauce. Cover pan and simmer until vegetables are barely tender, about 10 minutes.
Blend cornstarch, sugar, and beef broth and add to meat mixture with green onions. Cook, stirring constantly, until thoroughly heated and sauce is thickened.