Whizz the bread in a food processor to
crumbs, tip into a bowl, then whizz half the
sweetcorn until finely chopped. Add the
chopped corn, remaining whole corn, tuna,
cheese, spring onions and some seasoning
into the bowl with the bread and mix well.
Add the egg, bit by bit (you may not need it
all), until the mixture is sticky enough to be
shaped into four even-size burgers.