One thing you're probably never going to see in your next sushi roll, however, is wild-caught salmon. While farm-raised salmon gets a bit of a bad rap sometimes, it's actually much safer to eat ...

Place one of the nori sheets on top ... Wet the blade of a sharp knife and use it to slice both sushi rolls into 2cm/¾in slices. Keep wiping the knife as you go along as it makes it much easier ...