If using lamb shoulder, remove any silver skin, tough sinew, or hard pieces.
Chop the lamb and tail fat together with a zırh or a large sharp knife until the mixture is fine but still has a little texture. You can also pulse it briefly in a food processor, but don’t turn it into a paste.
Place the chopped lamb mixture in a large bowl. Add the salt, pul biber, and red pepper paste.
Mix well with your hands for a few minutes, until the mixture feels sticky and holds together.
Cover and refrigerate for at least 1 hour, or overnight if you have time.
Divide the mixture into 4 equal portions.
Keep a small bowl of water nearby and wet your hands lightly before shaping. Press each portion firmly around a flat metal skewer and shape it into a long, flat kebab.
Cook over hot charcoal or on a BBQ for 15 to 20 minutes, turning a few times, until browned and cooked through.
For a griddle pan, cook over medium-high heat for 10 to 12 minutes, turning carefully.
For the oven, preheat to 400°F / 200°C. Place the kebabs on a wire rack over a lined baking sheet and cook for 18 to 20 minutes, turning halfway through.
Serve hot with lavash, grilled tomatoes, grilled peppers, sumac onions, and salad.