This is a simple sandwich, but so good that author Tom Robbins wrote that this would be his request for a last meal, should he ever find himself in a position to request one. And do do it right, he would request the makings, and do it himself. It may seem silly to have instructions for this, but because of the particular ingredients, only this sandwich has the required taste.
So, he would need.
2 slices of bread for each sandwich. In this case, the bread needs to be Wonder bread or similar - the synthetic, squishy, air "bread" everyone knows from school sandwiches. (the bread in the picture is not Wonder bread)
1 large very ripe tomato, preferably from your own garden, or a farmer's market. the quality and taste of the tomato is essential for this to taste right. It should be so soft that it has to be cut with a serrated knife. No plum or Roma tomatoes - you need a big one,
Hellmann's mayonnaise, salt & pepper
Slather both slices of bread with mayonnaise, salt and pepper to taste. Plenty of salt is good. Cut the tomato into thick slices (about 1 cm). Layer them on one slice, add more salt to taste, top with the other slice. Push down hard on the top of the sandwich with your hand or the bottom of a plate, to meld the juices with the mayonnaise.
Simple, quick, delicious.