Combine tuna, olives, tomato, pepper and mayonnaise in a mixing bowl. Spread soft margarine on one side of the bread and set aside.
Spread the mixture over one slice of white bread and top up with another slice of buttered wholemeal bread.
Spread another layer of mixture on top of the wholemeal bread and top up with another slice of white bread.
Add cucumber, carrot, alfalfa and egg slices. Press on lightly and cut into a triangle.
Wrap up with cling film wrap. Refrigerate for at least an hour before serving or preferably overnight if you are having it for breakfast. Just before serving, prick a toothpick in the centre of the triangle, with a cherry on the tip.