Lay the dough on baking paper in the pie dish and pierce the dough base all over with a fork. Put in the fridge.
Stir together the milk, flour, eggs, salt, pepper and herbs. Grate the raclette cheese with a rösti grater and add in. Cut the spring onion, including the green stalk, into thin rings and mix in. Stir the topping sauce mixture well and pour on the dough.
Cut the courgettes lengthwise into thin strips with a peeler or vegetable slicer. Lay on the dough in a weaving pattern. Bake for 30-35 mins. on the lowest shelf of the oven, preheated to 200°C. Serve warm.