In a 6-qt. stockpot, heat oil over medium-high heat; saute onion until lightly browned, 3-4 minutes. Add garlic; cook and stir 1 minute. Stir in curry paste and sugar., Stir in vegetables, garbanzo beans, 3 cups broth, tomatoes and coconut milk; bring to a boil. Reduce heat; simmer, covered, until vegetables are tender, 35-40 minutes., Stir in remaining broth; heat through. Serve with cilantro and, if desired, lime wedges and rice.