Beef Zrazy with Mushroom Filling

Fry champignon mushrooms (300 g) with some of the onion (80 g) for 10 minutes, season with table salt (2 g), and cool. Mix beef (800 g) with the remaining onion (160 g), egg (50 g), table salt (4 g), and black pepper (2 g).

Shape a patty, add the filling, and enclose it with the meat. Without optional breadcrumbs, fry the zrazy in olive oil (15 g) until browned.

Finish covered for 7 minutes.