Heat oil in nonstick skillet over medium heat. Add onion, celery, bell pepper and garlic. Cook 4 to 7 minutes or until vegetables are tender and begin to brown, stirring occasionally. Transfer vegetables to large bowl; let cool 5 minutes.
Preheat oven to 400°F. Combine Ground Beef, vegetables, rice, egg and Cajun seasoning in large bowl, mixing lightly but thoroughly. Shape into 24 (1-1/2 inch) meatballs.
Place meatballs on rack in broiler pan that has been sprayed with nonstick cooking spray. Bake in 400°F oven 16 to 19 minutes or until 160°F. Serve with hot sauce, as desired.
Nutrition information per serving: 57 Calories; 27 kcal Calories from fat; 3 g Total Fat; 1 g Saturated Fat; 2 g Monounsaturated Fat; 20 mg Cholesterol; 83 mg Sodium; 3 g Total Carbohydrate; 0.1 g Dietary Fiber; 4 g Protein; 0.5 mg Iron; 1.3 mg Niacin; 0.1 mg Vitamin B6; 0.4 mcg Vitamin B12; 0.9 mg Zinc; 4.2 mcg Selenium; 17.6 mg Choline;