01 -
Start bacon in an unheated pan over medium heat and cook until crisp. Set on paper towels but keep the fat in the pan.
02 -
Smear pesto across all bread pieces. Add mozzarella, tomato slices, and bacon strips on two bread pieces, then cap with remaining bread, pesto facing inward.
03 -
Warm pan on medium flame. Butter the sandwich tops and place them down in the pan. Cook about 3-4 minutes till they're golden brown.
04 -
Butter the tops, turn them over, and cook another 2-3 minutes till they're brown and the cheese gets melty. Let them cool briefly before slicing.