Cut everything up. Fry the onion in a big pot till soft, put in the chilli, garlic and cumin seeds, fry for two minutes.
Put in the pumpkin, sweet potato and carrots. Top up with enough water to cover them and season with salt and pepper. When the veggies are soft enough to cut them in half with a folk (about 20 mins) take them off the heat and blend them with the coconut milk and nutmeg.