For the vegetable quiche, knead the flour with the other ingredients in a baking bowl until you get a smooth dough that separates from the edge of the bowl.
Form the dough into a ball, cover with a piece of kitchen roll and let rest in a warm place for at least 1 hour until the dough has doubled in volume.
Meanwhile, for the topping, blanch the tomatoes, rinse, peel off the skin, cut out the stem and slice the tomatoes.
Wash, dry and dice the zucchini. Peel shallots and garlic. Halve and pit the olives. Finely chop shallots, garlic, olives and capers. Mix with the zucchini and all the herbs and spices.
Preheat the oven to 200 °C.
Fold the dough and knead again briefly. Brush the baking tray with butter. Roll out the dough to the size of the baking tray, place it on top, press it into the corners with the heels of your hands and pull it up a little at the edges.
Now place the zucchini mixture on the dough, place tomato slices on top. Season with salt and pepper, drizzle with olive oil and let rest again for 20 minutes.
Put the baking tray in the oven and bake the quiche for 30-40 min.
About 10 minutes before the end of the cooking time, grate the feta cheese on top, drizzle another dash of olive oil and gratinate the vegetable quiche until golden brown.