Heat the oil over medium-high heat in a large soup pot. Add the onions, carrots, and celery and sauté for 8-10 minutes. Stir in garlic and cook for 2 minutes, then add the cumin, chili powder, coriander, cayenne pepper and oregano. Sauté for 1-2 minutes, until fragrant. Add the chickpeas, bell pepper, tomatoes, bay leaf and vegetable stock. Bring to a boil. Reduce the heat to low, and simmer for 15 minutes, adding the cilantro and vinegar towards the end, and remove the bay leaf.