Sardines - how to butterfly
Remove scales (de-scale)
Move the tip of the knife from the tail towards the head to scrape off the scales.
Chop off the head
Place the knife at the base of the pectoral fin and chop off the head in one motion.
Remove the innards
Cut away the edge of the belly from the head to the anal fin with a knife. Open the belly and use the knife to scrape out the innards.
Split open with hands
At this point, wrap the innards up in a newspaper, throw these away and rinse the sardine with water and then pat dry to remove excess moisture. Put your thumb inside the cut near to the top of the backbone, then slide this down towards the tail to split open.
Remove the backbone
Use your fingers to fold the end of the backbone near the tail, then carefully pull out the bone in the same direction.
Remove the stomach bones
Lay the knife flat and slice away the stomach bones. This completes the butterflying process.