Preheat your panini grill or a grill pan over medium heat.
One side of each slice of bread, if you prefer. Side Note: I always cook my paninis dry so they are extra crispy.
Place a little bit of mozzarella on top of one slice of bread. Add the tapenade to the top of the cheese followed by the tomato slices and a little more cheese. Place the other piece of bread on top.
Place on your panini pan (or grill pan).
Cook for 5 minutes or until crispy and golden brown on both sides.