Lightly sweat the onion, ginger and chilli in butter. Then sweat the pumpkin and carrots. Possibly add a little butter. Deglaze with the white wine and let it boil down a little.
Then fill up with the vegetable stock, add salt and simmer for about 20 minutes. Add the cream and purée finely with the hand blender. Add Worcestershire sauce, sugar and lemon zest, season with nutmeg, salt and pepper.
Put the basil leaves cut into strips on top after serving.