If using refrigerated pie crust, grease the springform and gently press the crust into the pan, leaving about 1/2 inch or so margin along the top. If making the dough yourself, once the yeast dough has risen, butter a medium-sized
springform (9 inches or so) and spread out the yeast dough on the bottom and up the sides (leaving about ½ inch from the top). The dough will keep retracting, just work fairly quickly and then immediately pour the onion mixture into it (it will hold the dough in place), sprinkle a few caraway seeds on top, and put it in the oven.