Mix all of the ingredients together with a fork until well combined. Drain the salad in a large colander to remove excess liquid.
Butter the slices of bread. Pan-fry one of the slices, buttered side down, with a slice of cheese on top. Set the slice aside: this will be the middle slice of the sandwich. On a second slice of bread, place another slice of cheese on the unbuttered side, then some tuna salad and more cheese. Top with the already browned slice, then add some tuna salad, a slice of cheese and the last slice of bread, buttered side out. Pan-fry the sandwich for 3–4 minutes on each side over very low heat. Cut the sandwich on the diagonal, then proceed in the same way for the second sandwich.
© 2013 All rights reserved. Published by Murdoch Books.