Roughly chop the onion, garlic, parsley, and coriander. Add them to a blender or food processor and pulse until very finely chopped, almost like a paste, scraping down the sides as needed.

Transfer the herb mixture to a fine sieve set over a bowl. Press firmly with the back of a spoon or your hand to squeeze out excess liquid, until it looks damp but not wet.

In a large mixing bowl, combine the drained herb mixture with the beef mince, cumin, ground coriander, smoked paprika, salt, and black pepper. Use your hands to mix until everything is evenly combined, then stop so the meat does not become dense.

Lightly grease a sheet pan with olive oil, making sure the base and corners are coated in a thin layer.

Spread the kofta mixture evenly across the pan in a layer about 1 inch thick. Smooth the top so it is level from edge to edge.

Use a round cake cutter or a sharp knife to score vertical lines, then horizontal lines, creating small rectangles. Cut almost to the bottom without separating the pieces.

Bake at 400°F (200°C) for 20–25 minutes, until the top is browned in spots and the meat is cooked through. For deeper color, place under the broiler for 3–5 minutes, watching closely.

While the kofta bakes, add tahini and lemon juice to a small bowl. Whisk, then add hot water a spoonful at a time until the sauce is smooth and pourable. Season with salt and pepper to taste.

Dice the tomato and cucumber into small pieces. Place in a bowl, sprinkle with sumac, drizzle with olive oil, and season lightly with salt and pepper. Toss gently to coat.

Follow the score lines to cut the kofta into rectangles. Serve inside flatbreads or on plates, drizzle with tahini sauce, and add the sumac tomato-cucumber salad on the side or tucked into wraps.