Add onion, celery, and carrots to pan. Cook stirring occasionally until slightly tender; about 4 minutes. Stir in broth, tomatoes, chickpeas, and pepper. Bring to a boil. Reduce heat to medium low and simmer 20 minutes. Stir in kale. Cook until wilted; about 5 minutes. Drizzle each serving with reserved garlic oil. Serve with bread or crackers.