1. Preheat grill to medium-high heat.
2. Place burger patties on the grill and cook for three minutes.
3. Flip burger patties and cook for an additional three minutes, or until internal temperature reaches 160ºF.
4. Add one slice of fresh mozzarella to each patty and cook with grill lid on for 30 seconds, or until cheese is melted.
5. Add cheeseburger patties to the bottom half of each bun. Top with one slice of fresh tomato.
6. Spread two tablespoons of pesto onto the top half of each bun. Place top on cheeseburger patties and enjoy!