Anyone who buys their fish "round" knows that they are not yet gutted. This is a sign that the fish is particularly fresh - after all, the innards are the ones most likely to spoil.
Sometimes you're lucky and get a Rogner - a female fish. If the roe bags are still full, you also have a real delicacy here.
This post focuses on preparing the roe, for example as an accompaniment to salads, but also as an independent dish with your own side dishes.