Make the Yogurt Sauce: In a small bowl, combine the Greek yogurt, lemon juice, olive oil, garlic powder (or fresh garlic), cumin, salt, and pepper. Stir until smooth and refrigerate until ready to serve.
- Prepare the Lamb: In a large skillet, heat the olive oil over medium heat. Add the chopped onion and garlic, and sauté for 3-4 minutes, or until softened.
- Add the ground lamb to the skillet and cook, breaking it up with a spoon, until browned and cooked through, about 7-8 minutes.
- Stir in the cumin, coriander, cinnamon (if using), salt, and pepper, and cook for another 1-2 minutes, allowing the spices to toast and become fragrant.
- Assemble the Pitas: Warm the pita breads in a dry skillet or microwave for a few seconds until soft and pliable.
- Spoon the spiced lamb mixture onto the pita breads. Top with a generous amount of yogurt sauce and garnish with fresh parsley.
- Serve immediately and enjoy!