Preheat the oven to 180°C.
Cut the tops of the pumpkins, creating a lid, then scoop out the seeds and the membranes.
Mix the cream with the cornstarch and the Kirsch. Grate in the cheese. Add salt and pepper to taste, then a few shaving of grated nutmeg. Mix thoroughly.
Fill the pumpkins with the mixture, put the "lid" on, and put them a baking tray. Roast for 30-45 minutes. It is ready when the pumpkin flesh is tender (check with a fork).
Serve hot - and do scoop the pumpkin flesh into the creamy cheese!