Step 1: Prepare the Tzatziki: In a medium bowl, combine Greek yogurt, grated and squeezed cucumber, minced garlic, chopped fresh dill, lemon juice, olive oil, salt, and pepper. Mix well. Cover and refrigerate for at least 15 minutes to allow flavors to meld.
Step 2: Prepare the Burger Mixture: In a large bowl, combine the ground chicken, crumbled feta cheese, fresh dill, fresh mint, fresh parsley, minced garlic, diced red onion, lemon zest, salt, and black pepper. Using your hands, mix gently until just combined. Be careful not to overmix, as this can lead to tough burgers.
Step 3: Form the Patties: Divide the mixture into four equal portions. Gently shape each portion into a ¾-inch thick patty, slightly wider than your burger buns. Create a shallow indentation in the center of each patty with your thumb to prevent bulging during cooking.
Step 4: Cook the Burgers: Heat a grill or large non-stick skillet to medium-high heat (approx. 400°F / 200°C) and lightly oil the grates/pan. Cook the patties for 5-7 minutes per side, or until they are golden brown, cooked through, and reach an internal temperature of 165°F (74°C). Alternatively, air fry at 375°F (190°C) for 12-15 minutes, flipping halfway.
Step 5: Assemble and Serve: Lightly toast the burger buns or warm the pita bread. Spread a generous amount of tzatziki on the bottom bun/pita. Place a cooked Greek chicken patty on top, then layer with lettuce, tomato slices, red onion, and any other desired toppings. Add another dollop of tzatziki and the top bun/pita. Serve immediately.