In a large mixing bowl, combine ground chicken, rosemary, lemon zest, breadcrumbs, egg, garlic, salt, and pepper. Mix until well combined.

Divide the mixture into equal portions, roll into balls, and flatten into 3-inch patties.

Heat olive oil in a large skillet over medium heat for about 2 minutes.

Add the patties to the skillet, cooking for 4–5 minutes on each side until golden brown and cooked through.

Transfer cooked patties to paper towels to drain excess oil and let rest for a minute before serving.