01 - Squeeze excess moisture from the grated cucumber using a clean kitchen towel or cheesecloth. Combine Greek yogurt, drained cucumber, minced garlic, fresh dill, lemon juice, olive oil, salt, and pepper in a mixing bowl. Stir until smooth and well blended. Refrigerate until ready to serve to allow the flavors to develop.
02 - In a large mixing bowl, combine ground turkey, breadcrumbs, egg, minced garlic, grated onion, chopped parsley, chopped mint, dried oregano, ground cumin, salt, and black pepper. Gently fold the mixture until just evenly combined, being careful not to overwork the meat.
03 - Portion the turkey mixture and roll into 18 to 20 uniform walnut-sized meatballs, approximately 1.5 inches in diameter. Place on a plate or tray and keep chilled until ready to cook.
04 - Pan-Fry: Heat olive oil in a large nonstick skillet over medium heat. Add meatballs in batches and cook for 8 to 10 minutes, turning regularly, until golden brown on all sides and cooked through to an internal temperature of 165°F. Bake: Preheat oven to 400°F. Arrange meatballs on a parchment-lined baking sheet and brush or spray lightly with olive oil. Bake for 15 to 18 minutes, turning halfway through, until golden and fully cooked.
05 - Arrange the cooked meatballs on a serving platter with a generous dollop of tzatziki. Garnish with fresh herbs and lemon wedges. Serve alongside warm pita bread or a crisp side salad if desired.