Roasting whole makes the pumpkin much easier to handle and improves the sweet nutty flavour. Make a big pot at leisure while the pumpkin is in season and freeze leftovers.
Preheat the oven to 200°C. Place the pumpkin, and the garlic on a lightly greased large oven tray lined with non-stick baking paper. Drizzle with the oil and sprinkle with salt and pepper.
Cook for 1 hour until the pumpkin is soft. Set aside until cool enough to handle. Peel and scoop out the flesh of the pumpkin. Discard seeds. Remove the garlic from its skin.
Heat a dash of oil in a large pot. Add the leek, carrot, celery and cook for a few minutes. Add the fresh herbs, roasted garlic and pumpkin flesh, then pour in the stock. Bring to boil and simmer for 20 minutes.
Blend the soup in a blender or using a hand-held stick blender until smooth. Place the soup over high heat and bring to the boil. Add the coconut cream and season to taste.
Serve in soup bowls, drizzle with tahini, sprinkle some pumpkin seeds, fresh herbs and chilli (if liked) accompanied with herb buttered toasts. To make the herb butter, simply mix in the chopped herb with softened butter.