In a large bowl, mix together olive oil, yogurt, grated onion, cumin, paprika, salt, and black pepper. Add the thinly sliced meat to the marinade, ensuring each piece is well coated. Cover and refrigerate for at least 1 hour, or ideally overnight, to let the flavors deepen.

To prepare the tomato sauce, melt the butter in a saucepan over medium heat. Add minced garlic and cook until fragrant, about 1 minute. Stir in the crushed tomatoes, sugar, salt, and black pepper. Let the sauce simmer for 15-20 minutes, stirring occasionally until it thickens. Adjust seasoning as needed and keep warm.

Preheat your oven to 180°C (350°F). Place the marinated meat on a baking sheet lined with parchment paper or on a rack. Roast for 15-20 minutes, turning halfway through, until the meat is browned and tender. Alternatively, grill or pan-sear the meat over high heat until nicely charred and cooked through.

While the meat cooks, cut the pita or flatbreads into bite-sized pieces. Spread them on a separate baking sheet and toast in the oven for about 5 minutes until lightly crisped. This will add texture to the base of the dish.

In a small pan, melt the remaining 2 tbsp of butter over low heat. Allow it to brown slightly for a nutty flavour, but be careful not to burn it. This will be drizzled over the kebab for an authentic finishing touch.

To assemble, spread the toasted bread pieces on a large serving platter. Arrange the roasted or grilled meat slices over the bread, ensuring even coverage for balanced bites.

Pour the warm tomato sauce generously over the meat, allowing it to seep down to the bread layer. Dollop the whisked yogurt around the edges or in the centre, depending on your preferred presentation.

Drizzle the browned butter over the assembled kebab, letting it enhance the flavors of the tomato sauce and yogurt. Garnish with chopped parsley and serve immediately. İskender Kebab is best enjoyed hot, with a side of extra yogurt or a light salad for a balanced meal.