Slice beef while frozen into 1/2"x 1/2"x1/4" pieces. Combine 1/4 cup soy sauce, 1 teaspoons sugar and beef. Marinate 1/2 hour. Cut up tomatoes and green pepper; heat oil in a large skillet. Add garlic and ginger. After a minute, remove garlic clove; add green pepper. Add beef and its liquid and saute 3 minutes. Add tomatoes. Immediately blend cornstarch with remaining (2 T.) soy sauce and add. Gently stir the entire mixture and cook 2 more minutes. Serve over 6 portions of cooked rice.