In deep 12-inch skillet, heat oil over medium heat. Add sweet potato, onion, zucchini and green pepper; cook, stirring till vegetable are tender, 8 to 10 minutes. Add curry powder and cumin, cook 1 minute.
Add garbanzo beans, tomatoes with their juice, broth and salt and pepper. Heat to boiling over high heat. Reduce heat to medium low; cover skillet and simmer till vegetables are very tender but still hold their shape, about 10 minutes longer.