In a stockpot, heat oil over medium-high heat. Stir in kohlrabi, celery, onions and carrots; cook 5 minutes or until onions are softened. Add garlic, salt and pepper; cook and stir 5 minutes., Stir in stock, beans and bay leaves. Bring to a boil over medium-high heat. Reduce heat; simmer, covered, until vegetables are tender, 20-25 minutes. Add remaining ingredients; simmer 5 minutes more. Discard bay leaves.