Fresh fish (from the sea anyway) isn't that much of a thing at all in Poland.
Weirdly enough the coastal area where I'm from that was also the case. Most locals (as opposed to tourists or transplants) didn't eat much fish at all. We did eat other seafood (crab, lobster, shrimp, oysters....) but plain fish? meh My favorite was rock shrimp which was very cheap because it was ugly and a lot of work to prepare (about 40 mintues to shell and de-vein enough for two people) but soooo good with a taste between shrimp and lobster....
Recently, I've noticed fresh fish that's okay biedronka. I do like breaded and fried pollock (mintaj) served with boiled potatoes and sauerkraut salad
slice one medium onion into thin strips mix about a half teaspoon of salt and let sit about 0-15 minutes.
drain about a half kilo of sauerkraut well and keep the juice to drink (very healthy)
Cut the drained sauerkraut up into smaller bits. Mix with a a little salt, more pepper and two or so teaspoons of oil in a bowl.
Mix in the onions.
Grate one red apple over the top and then mix well....