In a saucepan, bring the vegetable stock and pumpkin pieces to the boil.
Reduce heat, cover and simmer for 10 minutes.
Add the rice and continue to simmer for 20 minutes, stirring regularly, or until the rice is soft and most of the liquid has been absorbed.
Stir through half the Parmesan and season with sea salt and pepper.
Serve sprinkled with remaining Parmesan.