Knead the flour, butter, milk and salt into a dough and then chill for about 30 minutes.
Prepare the gyros according to the package instructions, add the onion. Roll out the dough in a springform pan. Prick the dough with a fork. Put the fried gyros, tzatziki, onion on the dough, chop the feta and sprinkle over it. Bake for 30 minutes at 180 ° C.