Ah I know it was popular in Germany too, but I didn’t know about Poland. In France it’s also popular and a lot of restaurant serving meat have that on the menu but it’s often disappointing in restaurant because it’s prepared in advance and not at the order.

I’m not sure if I would trust already made tartare from supermarket, but I guess they have very strict rules to follow so it should be fine. The picture you sent is indeed grounded very small. In france the specialty is to cut it by knife in small rectangle and not ground it. You have a better texture when you chew it.