01 - 
                Smear a spoonful of pesto across one face of each bread slice, making sure it's spread out evenly.
              
              
              
                02 - 
                Take two bread pieces (pesto facing up) and pile on plenty of grated mozzarella or lay down 2 fresh mozzarella slices. If you want, sprinkle some Parmesan over the cheese. Top with the other bread pieces (pesto facing down) to finish your sandwiches.
              
              
              
                03 - 
                Lightly coat the outer sides of each sandwich with soft butter to get that nice golden crunch when you cook them.
              
              
              
                04 - 
                Warm up a non-stick pan over medium heat. Drop in your sandwiches and let them cook about 2-3 minutes on each side. Press them down gently with a spatula until they're golden brown and the cheese gets all melty.
              
              
              
                05 - 
                Take your hot sandwiches off the pan, cut them in half, and enjoy right away.