Combine the ground chicken, egg, bread crumbs, fresh basil, salt, Italian seasoning, garlic powder, ground pepper, and olive oil in a large bowl. Mix thoroughly with your (clean) hands, but be mindful not to over-mix.
Divide into four equal portions and form into patties roughly 4" in diameter and 1” thick.
To Pan Sear. Heat a well-seasoned cast iron or non-stick skillet over medium high heat. Add the oil and heat until it shimmers. Pan fry 5-6 minutes per side, or until golden brown and the internal temperature reaches around 160°F using an instant read thermometer. Top each burger with mozzarella cheese, then cover for 1 minute more to melt the cheese and bring the internal temperature to 165°F.
To grill. Heat a grill to medium high heat (375-400°F). Grill 4-5 minutes per side, or until the internal temperature reaches 160°F using an instant read thermometer. Top each burger with mozzarella cheese, then close the lid and grill for 1 minute more to melt the cheese and bring the internal temperature to 165°F.
Place each burger onto the bottom half of the bun. Top with 2 tablespoons of pesto, 1-2 tomato slices, and 3-4 fresh basil leaves. Place the lids on the buns and enjoy.
