Boil sweet potato, butternut and onion in 1.5 litres of water. Then purée all ingredients (discard water depending on the your preferred consistency of the soup). Set aside.
Remove the top of the pumpkin and keep the lid intact. Remove all seeds and excess flesh inside pumpkin. Place on a baking tray.
Add cream, garlic and thyme in a pan over the stove, just until cream is heated. Pour cream mixture into pumpkin, cover with pumpkin lid and place in pre-heated oven (150 C) for one hour.
Add the butternut and sweet potato soup into the pumpkin and half the parmesan cheese. Stir until the cream garlic mixture combines. Then sprinkle the remainder of the parmesan on top. Do not use the lid when placed in oven this time. Cook in oven for a further 45 min.
Serve in pumpkin shell. Decorate with thyme, pumpkin seeds and some shaved parmesan. When serving break off some of the soft pumpkin from the sides of the shell. Serve with fresh crusty bread.