Cut the fennel, zucchini and mushrooms into fine slices, season with salt, season with pepper and roast in olive oil until cooked to the bite on all sides. The vegetables can be placed together in a roasting pan or prepared separately in individual roasts. This is best done in a coated frying pan and takes no more than three to four minutes.
Then layer the fried vegetables in a gratin dish. Put the whipping cream in a saucepan and boil it by half. Grate the Parmesan cheese with a cheese grater, add about two tablespoons to the whipped cream and mix well. Spoon the thickened whipped cream with the Parmesan cheese over the vegetables and drizzle with olive oil. Now gratinate the whole thing under the broiler at the highest temperature for three to five minutes until you get a crispy brown crust.
Our tip: Zucchini are tender in taste and therefore also well suited for children.