In a large mixing bowl, combine ground chicken, crumbled feta cheese, finely chopped parsley, minced garlic, and a beaten egg. Use your hands or a spatula to gently mix until just combined.

Fold in diced tomatoes, Kalamata olives, diced red onion, and breadcrumbs. Season generously with salt and pepper. Mix until evenly distributed.

Divide the mixture into four equal portions, shaping each into a patty about ¾ inch thick. Refrigerate for at least 15 minutes.

Heat a tablespoon of olive oil in a non-stick skillet over medium heat. Cook patties for 5-6 minutes on each side until golden brown and cooked through.

Let the patties rest for a few minutes before serving. Serve warm, garnished with extra parsley or toppings like tzatziki.