01 - Lightly toast the bread slices until golden on the surface but still soft inside, if a crisper texture is desired.
02 - Spread an even layer of mayonnaise over one side of each bread slice.
03 - Arrange the tomato slices evenly across two of the bread slices, overlapping slightly for full coverage.
04 - Generously season the tomato layers with salt and freshly ground black pepper.
05 - Tear or layer fresh basil leaves over the seasoned tomatoes, if using.
06 - Drizzle the olive oil and balsamic vinegar over the tomatoes and basil for added depth of flavor, if desired.
07 - Place the remaining bread slices on top, mayonnaise side facing down, and press gently to set.
08 - Cut each sandwich in half using a serrated knife and serve immediately while the bread is still warm.