Spread sandwich filling onto a slice of bread.
Place tomato slices on the top third of the bread, the yellow peppers in the middle, and the lettuce on the bottom third.
On the second slice of bread, punch out six holes (three on each side) with an apple corer.
Place on top of the vegetables, and cut bread in half so you have two traffic lights.
Variations:
Try using any variation of a sandwich filling, like tuna.