01 - In a large mixing bowl, combine the ground beef, red onion, garlic, breadcrumbs, egg, parsley, mint, oregano, cumin, lemon zest, salt, and black pepper. Mix gently until just combined, being careful not to overwork the meat.
02 - With wet hands to prevent sticking, portion the mixture and roll into walnut-sized balls, yielding approximately 20 meatballs.
03 - Heat olive oil in a large nonstick skillet over medium heat. Fry the meatballs in batches, turning occasionally, until evenly browned and cooked through to an internal temperature of 160°F, about 8 to 10 minutes. Transfer to a paper towel-lined plate to drain.
04 - While the meatballs cook, whisk together the Greek yogurt, lemon juice, fresh dill, and minced garlic in a small bowl. Season with salt and pepper to taste.
05 - Arrange the hot meatballs on a serving platter alongside the yogurt sauce. Garnish with additional fresh parsley if desired.