Wash the Hokkaido pumpkin, cut in half, hollow out the core and cut into medium-sized pieces unpeeled. Peel and dice the carrots, potatoes, onion and garlic. Cut the leek into rings.
Sauté everything in olive oil in a tall soup pot and deglaze with the prepared hot vegetable stock. Simmer for 20 minutes over medium heat. Finely puree the vegetables with the magic wand, add coconut milk and briefly bring to the boil again. Season to taste with salt, pepper, sugar, lemon juice and nutmeg.
Roast the dried pumpkin seeds in a non-stick pan without adding any oil. Arrange the soup in deep plates or soup bowls and refine with 1 teaspoon each of pumpkin seed oil and the pumpkin seeds.