This is my favorite way to deep-fry fish. It produces an extremely crispy exterior and a tender, flakey interior. It is typically served with “chips” (french fries), and the frying oil may be used for both. When doing so, it is recommended to do the final fry of the fries after the fish as the fish can stay crispy in a warming drawer for a while and the fries usually do not hold up as well.
A full written recipe may be found here: https://cook.karylstein.com/g/family/r/beer-battered-fish