Grease a baking pan with oil and line it with the puff pastry. Lay out the slices so that they overlap. Line the edge with puff pastry as well.
Season the spinach with salt. Add the cheese, onions and eggs. Mix everything well and distribute the mixture evenly on the dough. Cover with the remaining dough sheets and leave a thick bead of dough on the edge. Brush with oil and bake at 220 ° C for about 45 minutes until golden brown.
Serve with buttermilk or whipped yogurt and green salad.