Thaw puff pastry overnight in the fridge. You can also prepare the fillings a day in advance, so in the morning you can quickly stuff somsa and burekas and bake. For meet filling you can take either ground meet or chop it into really small pieces. This way somsa tastes better, but it takes much more time. Also you can take combination of beef and lamb, or just beef. Meat filling should not be too dry. Some fat Is needed in it.