Heat the oven to 200°C (180°C in a fan oven) 400°F, gas 6.
Cut the courgettes in half and scoop out the seeds. Place on a baking tray lined with baking parchment.
For the soufflé, beat the egg yolks with the butter, parsley and nutmeg until fluffy. Stir in the grated cheese, cream and crème fraîche alternately. Beat the egg whites until stiff and fold into the mixture with the flour. Season with a pinch of salt.
Spoon the soufflé mixture into the hollowed courgettes and bake for approx. 15 minutes until golden brown. Serve at once.