Mix 2 table spoons of oil with the pumpkin and on spread out on a tray. Cook in the oven for 20 minutes. Take out of the oven and sprinkle the cumin and the pepper over the pumpkin, and cook for a further 10 min.
In a pan sweat the leeks with the rest of olive oil. Add the ginger and cook for a few minutes
Put all the vegetables in a blender and liquidise. About 4 minutes.
Pour the soup back in the pan and add the water. Cook for a further 7 minutes.
When served add a crushed, pink peppercorns and thyme