In a small bowl, whisk pesto, vinegar, and sugar until smooth. Slowly drizzle in olive oil, whisking constantly until vinaigrette is smooth and combined.
Season vinaigrette with salt and pepper to taste if needed. Store vinaigrette in refrigerator until ready to use.
Caprese Chicken Burgers
In a large bowl, combine ground chicken, breadcrumbs, egg, garlic, salt, and pepper. Very gently knead until just combined. Form mixture into 4 patties.
Preheat a grill to 375F.* Grill patties either on a greased grill pan or a sheet of nonstick aluminum foil (they tend to stick to the grill grates if you put them on directly) Grill chicken burgers, flipping once until golden-brown and meat registers 165F (about 8-10 minutes of cooking)
Transfer burgers to a plate. Place a slice of mozzarella cheese over each patty and lightly tent plate with foil to allow mozzarella to melt slightly for 5 minutes.
Place a lettuce leaf on each bottom of toasted buns. Top with burger patties, tomatoes, and basil leaves. Drizzle burgers with pesto vinaigrette. Serve burgers immediately and enjoy!
Notes
* If you do not have access to a grill, cook burgers on stovetop instead. Heat a large skillet over medium high heat and swirl a little vegetable oil in pan to coat. Add patties and cook until golden brown on each side and meat registers 165F.Burgers are best if served immediately after they are made.