flounder obviously is a very different shaped fish than most others so filleting it can be a challenge step one make an incision just above its head down to the bones but don't cut through the bones step 2 you make another incision following the fish's lateral line you want to go right along it again right down to the bones but not through them step 3 now that the fish has been split open like this you can insert the knife and slide it right along those bones to take the meat off next we're going to separate the fillet from the fish by cutting along the skin here's where a lot of people make a mistake and cut the Flay all the way off if you leave it attached it makes it really easy to skin the fillet there now we have a nice chunk of flounder second half the flounder comes off the same way but you want to watch out for the belly section here then just slide that fillet right off of there the second half of the fish goes exactly the same way just flip it over make her cut here follow the lateral line and slide each playoff believe me you're in for a good meal