1) In a large pan, gently soften the leeks and carrots in the olive oil with the bay leaves.
2) Preheat oven to 185c.
3) Cut pumpkin into wedges, leaving the skin on. Carefully remove the seeds setting to one side, and make sure the stingy innermost part of the flesh remains attached to the pumpkin wedges.
4) Place on a baking tray and sprinkle with salt and pepper. Bake at 185c for approx. 45 minutes or until soft.
5) Once soft, remove the pumpkin from the oven and remove the skin. Also carefully remove the stringy innermost part of the flesh and set aside.
6) Break the remaining baked pumpkin flesh up and add to the softened leeks and carrots, along with the chopped potato.
7) Gradually add the vegetable stock and cook until the potato is soft.
8) Remove the bay leaves.
9) Place everything in a blender with a little salt, white pepper, freshly grated nutmeg, and a couple of spoonfuls of the mascarpone.
10) Blend until completely smooth, check seasoning and adjust to taste.
11) Toast the pumpkin seeds in a hot pan.
12) Fry the sage leaves and set aside.
13) Make sure the soup is piping hot, then divide between several bowls.
14) Garnish each bowl with a few pieces of the innermost part of the pumpkin that you set aside earlier – these should have a great flavour and be slightly charred from the roasting.
15) Finish each bowl with a few sage leaves, a couple of dollops of mascarpone, a drizzle of pumpkin seed oil, and a sprinkle of toasted pumpkin seeds.