To coat the chicken, dip the chicken breasts first into the seasoned flour, then into the egg and finally into the Special K crumbs.
Fry/bake the chicken until golden, crunchy and cooked through.
To make the tzatziki, simply combine all the ingredients in a bowl.
To make the sandwich, spread a generous amount of tzatziki on half of the slices of bread, top with 2 crunchy chicken fillets, baby lettuce and top with the remaining bread.