Knead all the ingredients for the dough together and leave them to rest in the refrigerator for about 30 minutes in a glass foil.
Peel both types of onion and cut into quarter rings, peel the carrots and cut into slices, cut the zucchini into quarter slices, cut the leek into rings. Onions and bacon in a saucepan do not braise the vegetables, except the tomatoes, and braise them briefly. Let cool down briefly
Roll out the dough in a greased springform pan with a rim, insert the base with a fork and press the edge with a fork, distribute the steamed vegetables on the dough
Mix the sour cream, eggs, salt, pepper, nutmeg and the pamesan with each other and spread on the vegetables, cut the tomatoes into slices and spread on the sour cream mixture on the outside to form a ring and spread the cheese in the middle
Put the cake in the oven preheated to 225 degrees and bake for 40 minutes