Preheat the oven to 150°C / 300°F / Gas mark 2.
Line 2 baking trays with greaseproof paper.
Cut lids off each pumpkin and scoop out the seeds and strands.
Put the pumpkins on the prepared baking trays.
Meanwhile, heat the cream, milk, garlic and most of the thyme, with plenty of salt and pepper.
When hot, pour into the pumpkin and stir in 50g of the parmesan cheese. Put on the lids.
Bake for 1½ hours.
Remove from the oven, then turn up the heat to 200°C / 400°F / Gas mark 6.
Remove the lid, sprinkle with pepper and the rest of the cheese, then bake for a further 15 minutes more until golden.
Scatter over the remaining thyme leaves.
Allow to cool slightly then mix gently within the pumpkins to combine more of the cooked pumpkin flesh to mingle with the creams and cheeses.
Serve with crusty bread.