Heat the oil in a large, heavy pot. Add the onions, garlic, ginger,and cilantro; and saute for 5-10 minutes until the onions are very soft and translucent.
Add the cauliflower and sweet potatoes along with the red curry paste, curry, turmeric, coriander and cumin. Season with salt and pepper and saute for 5 more minutes until the vegetables are well coated with the curry paste and spices and the dish becomes very fragrant.
Next, add the canned tomatoes with their juices, chickpeas, coconut milk and as much water as you'd like depending on the thickness preference. I usually do about 2 cups of water so that it covers the vegetables slightly.
Bring to a boil, then turn the heat to low. Simmer for 20 minutes, stirring occasionally, until the cauliflower and potatoes are fork tender.
Serve over rice and garnish with cilantro, if desired