To prepare the burgers, preheat grill or grill pan over medium-high heat.
Squeeze the shredded zucchini in small handfuls to release much of the water.
In a large bowl, combine the zucchini, onion, ground chicken, egg, breadcrumbs, salt, and pepper using clean hands. Form the mixture into four patties.
Grill the patties on the preheated grill or grill pan for 6-7 minutes, then flip, and grill an additional 3-4 minutes, or until the internal temperature of the burgers reads 160°F.
While the burgers are cooking, mix together all the mayo ingredients.
Place the burgers on buns and top with mayo, plus other desired toppings. Enjoy!
Notes
Make this delicious burger completely grain-free by using gluten-free panko breadcrumbs and a gluten-free bun!