In a 6-qt. stockpot, heat oil over medium heat; saute onion until tender, 3-4 minutes. Add garlic and pepper; cook and stir 1 minute., Stir in meatballs, carrots and broth; bring to a boil. Reduce heat; simmer, covered, 5 minutes. Stir in beans and escarole; return to a boil. Reduce heat; simmer, covered, until escarole has wilted, about 10 minutes. If desired, top servings with basil. Freeze option: Freeze cooled soup in freezer containers. To use, partially thaw in refrigerator overnight. Heat through in a saucepan, stirring occasionally.