Peel and chop the pumpkin into small pieces. Mix together the chilli powder and lemon juice. Add to the pumpkin and toss well to coat. Place the pumpkin in a roasting tin and bake for 45 minutes or until very soft.
Reserve 50g of the cooked pumpkin and 2 cheese triangles. Transfer the remaining cooked pumpkin to a saucepan, add the stock and the remaining cheese triangles. Season and simmer for 15 minutes.
Blend the soup and serve with a garnish of the reserved roasted pumpkin and cheese triangles, plus the parsley.