a deceent sandwich needs 3 slices of bread for starters, so that you can spread the ingredients on all 3 slices and not have the problems with cross contamination of spreads and none spready stuff

so dairylea on 3 slices first
then one slices gets some marmite
then another slice gets some sandwich spread
yet another slices gets the sandwich filler
the 3rd slice gets some lime pickle
then you can add the slices of cheese
the slices of ham
the letuce
then mash it all up and you chow down