Carefully cut 3 holes (as shown in my photo tutorial above) into 4 pieces of the bread. You can use the wide end of a pastry tip, a water bottle lid or a small cookie cutter to make the holes.
Spread on a little mayonnaise (or other spread). Place a slice of tomato over the top hole and a couple of spinach leaves over the bottom one. Place cheese on top and gently press down then add turkey or ham, if desired.
Spread a little mayonnaise (or other spread) on the other 4 pieces of bread and place on top.
Gently turn the sandwich over and serve.