Prepare the rolls (check the recipe). If the buns were prepared on a different day, first put them in a toaster or oven and warm them up for a while.

Wash, dry, and cut the avocado in half along the middle. Sprinkle the half with the seed with lemon juice, wrap tightly in plastic wrap, and refrigerate (use to prepare another meal within a few days). Remove the flesh from the other half with a spoon and cut it into slices. Wash, dry, and slice the tomato (remove the hard, green parts from the center). On a plate, lay out the buns, avocado, tomato, and mayonnaise. Season with salt and pepper to taste.