Thaw puff pastry at room temperature 1 hour before cooking.
It is necessary to peel 3 large onions of husk and cut them into half rings. In vegetable oil, fry the onions until golden brown.
Season the onions during the roasting process with ground black pepper. Preparing the fill: beat eggs with sour cream. Rub cheese on a coarse grater and add it to the egg mixture - mix.
Roll out and lay 2/3 of the thawed puff pastry into a mold, form small sides 4 cm high, and cut off excess dough.
We spread the fried onions on the dough. Then evenly distribute the egg and cheese fill. The beads must be bent toward the center.
Strip the remaining dough in strips and lay them crosswise in the form of a net. The grid can be greased with the remains of egg fill or with one egg yolk.
Bake onion pie in an oven preheated to 220С for 30 minutes. Serve both warm and cold.