In a large bowl, combine grated onions, minced garlic, olive oil, yogurt, cumin, black pepper, paprika, and salt. Mix well until the ingredients are fully integrated.

Add the thinly sliced lamb to the marinade. Ensure each slice is well coated. Cover the bowl with plastic wrap and let it marinate in the refrigerator for at least 4 hours, preferably overnight, to allow the flavours to penetrate the meat.

If you have a traditional Cag Kebab spit, prepare the fire with wood or charcoal until it forms a medium heat. Otherwise, preheat your oven to 200°C (390°F) if you're using an alternative method like an oven or grill.

Thread the marinated lamb slices tightly onto skewers or the rotisserie spit, alternating with fresh thyme or rosemary sprigs if desired for added flavour.

Place the skewers over the fire or in the oven. Cook slowly, rotating regularly until the meat is evenly browned and cooked through, about 1-1.5 hours depending on the thickness of the lamb slices.

As the lamb cooks, periodically baste it with leftover marinade to keep the meat juicy and enhance its flavour.

Once cooked, remove the skewers from the heat. Slice thin portions of the lamb directly from the skewers or spit, in the traditional Turkish style.

Serve the Cag Kebab with lavash bread, sliced tomatoes, and onions. Enjoy this flavorful and tender lamb with a side of ayran (a yogurt based drink) for an authentic experience.