Marinate the Lamb: In a bowl, mix the olive oil, garlic, oregano, lemon zest and juice, red wine vinegar, salt, pepper, and optional spices. Add the lamb and toss to coat. Cover and refrigerate for at least 4 - 6 hours. (24 hours if needed).
Make the Garlic Yoghurt Sauce: Combine all sauce ingredients in a bowl and stir until smooth. Taste and adjust seasoning. Chill until ready to serve.
Grill the Lamb: Thread lamb onto skewers. Preheat a grill pan or BBQ over medium-high heat. Cook skewers for 2–3 minutes per side, or until cooked to your liking. Rest for a few minutes.
Assemble and Serve: Serve lamb with pita, garlic yoghurt sauce and your choice of toppings. Don’t forget a squeeze of lemon!