Small round fish like herrings are often cooked whole because they are fiddly to fillet. Sometimes you may need to bone a large round fish if you are cooking it whole.
Scale and gut the fish in the usual way. Cut off the head and tail or leave them on if preferred. Extend the cut along the belly (used for gutting) so that it goes right to the tail.
Open the fish out, then lay it on its side on a board. Carefully cut the rib bones free from the flesh on the upperside.
Turn the fish over and repeat on the other side, working through to the backbone, being careful not to cut through the flesh.
With a pair of kitchen scissors, cut through the backbone as close to the head as possible. Hold the backbone at the head end and carefully pull it free. Snip it at the tail end so that it can be removed completely.
Check the flesh for any remaining bones, removing any small bones with tweezers.
Note: If it is a small fish, simply open it out, then lay it on a noard cut side down. Press firmly along the backbone with your ingers to loosen it. Turn the fish over and you should now be able to pull the backbone away with the ribs attached. Remove any fine bones that don’t come away, using tweezers.