You can find the recipe here, but it's only in Bulgarian and it's a bit different than how I made it. For those who have no idea what it says, and don't want to use translators:
The dough is a bit thicker than the usual for pancakes - 3 eggs, 200ml milk and 200g flour.
As for the filling - you can choose whatever meat you like, slice it into small pieces and fry it with mushrooms. Put on a leaf of salad, add mayonnaise and roll.