Place Pesto ingredients in a food processor and pulse until it is a nice pesto consistency, not a paste (pictured above). This only takes a few pulses.
Mix the ground chicken with the Panko, cheese, chili powder, lemon juice, soy sauce, and balsamic vinegar until well incorporated. Mix the pesto into this mixture (I use my clean hands to do this). Form into patties. This will make 4 or 5 depending on size.
Cover and refrigerate for a couple of hours (if possible) before grilling to give the flavors a chance to really come together. Grill burgers over medium-high heat, flipping once until desired doneness is reached. You can also cook these on medium-high heat in a cast iron skillet if it's not grilling weather or if you don't own a grill (a few minutes on each side). Serve on hamburger buns with garnishes of your choice. I used cheddar cheese, BBQ sauce and lettuce.
Recipe by Wishes and Dishes at https://wishesndishes.com/cheddar-and-spinach-pesto-chicken-burgers/