Pesto Mozzarella Grilled Cheese - Recipe

This is my FAVORITE Grilled Cheese Sandwich.  I have made this recipe for awhile now that I don't remember the original recipe.  Original recipe came from Tyler off Food Network. 

Pesto Mozzarella Grilled Cheesed Sandwich
-Sour Dough Bread
-Pesto (homemade or store bought - we use the Pine Nuts, Garlic kind of Pesto)
-Fresh Mozzarella Slices (in a pinch I have used shredded mozz. cheese, just as yummy)
-Butter

-Butter the outside of two slices of bread.
-Smear as much or as little of Pesto you want on the bread (I smear lots but only on one piece of bread)
-Layer cheese on top of Pesto.  Again as much or as less as you want.
-Close your sandwich with Butter side out (yeah goober here put butter inside once and was wondering why my bread wasn't toasting)
-Heat Griddle or Cast Iron Skillet
-When griddle is nice and hot, lay sandwich (butter side down) on griddle and cook to your liking of golden toasted bread. 
-Flip and repeat for other side of bread.

This is a little too Golden Brown and what will

happen if you heat the griddle too hot....still

yummy none the less.