01 - Combine Greek yogurt, grated cucumber, dill, garlic, lemon juice, olive oil, salt, and pepper in a medium bowl. Stir thoroughly until well incorporated. Cover and refrigerate until ready to serve.
02 - In a large bowl, combine ground chicken, breadcrumbs, crumbled feta, chopped red onion, parsley, minced garlic, oregano, cumin, salt, and pepper. Mix gently until just combined—avoid overmixing to prevent tough patties.
03 - Divide the chicken mixture into 4 equal portions. Shape each portion into a uniform burger patty, pressing lightly to form without compacting the meat too tightly.
04 - Heat olive oil in a large skillet or grill pan over medium heat. Place patties in the pan and cook for 5–6 minutes per side until golden brown and cooked through. Internal temperature should reach 165°F for safe consumption.
05 - Place lettuce leaves on the bottom half of each toasted bun. Top with a cooked chicken patty, followed by tomato slices and thin red onion rings. Finish with a generous spoonful of tzatziki sauce and cover with the top bun.
06 - Serve immediately while patties are still warm. Offer extra tzatziki sauce on the side for those who prefer additional sauce.