Heat the oil in a large frying pan. Add the zucchini and cook over a moderate heat for 10 minutes, stirring frequently. Add the sugar and season with salt.
Put a baking tray in the oven and preheat to 200°C. Lightly grease a 1.5 litre soufflé dish with a little of the butter.
Melt the remaining butter in a saucepan over a low heat. Add the flour and cook for 30 seconds, stirring with a wooden spoon. Gradually pour in the milk and bring to the boil, stirring constantly, until thickened. Stir in the cheese until melted, then season with nutmeg, salt and pepper. Remove the pan from the heat and leave to cool.
Whisk the egg whites until stiff. Beat the egg yolks into the cooled sauce, then fold in the zucchini and egg whites. Pour the mixture into the soufflé dish and sprinkle with cheese.
Set the dish on the hot baking tray and bake for about 45 minutes until risen and golden brown. Serve immediately.
The soft cheese is sold in 80 g boxes and is labelled ‘ail & fines herbes’. You will find it with the other cheeses.