01 - Wrap the grated cucumber in a clean kitchen towel and squeeze firmly to remove all excess moisture. In a mixing bowl, combine the drained cucumber with Greek yogurt, minced garlic, dill, lemon juice, olive oil, and season with salt and pepper. Stir until smooth and well blended. Cover and refrigerate for at least 15 minutes to allow the flavors to meld.
02 - In a large mixing bowl, combine the ground turkey, breadcrumbs, egg, minced garlic, grated onion, parsley, mint, oregano, cumin, salt, and pepper. Gently fold the mixture with your hands until just combined, being careful not to overwork the meat.
03 - Portion the mixture into 18 to 20 evenly sized walnut-shaped meatballs, rolling each gently between your palms. Arrange them on a plate or tray as you work.
04 - For pan-frying: heat olive oil in a large nonstick skillet over medium heat. Add the meatballs in batches and cook for 8 to 10 minutes, turning every couple of minutes, until golden brown on all sides and cooked through to an internal temperature of 165°F. For baking: preheat the oven to 400°F and arrange the meatballs on a parchment-lined baking sheet. Lightly brush or spray with olive oil and bake for 15 to 18 minutes, turning halfway through, until golden and fully cooked.
05 - Arrange the cooked meatballs on a serving platter and garnish with fresh herbs. Serve alongside a generous dollop of tzatziki sauce, lemon wedges, and warm pita bread or a crisp side salad if desired.