Chill the lamb and lamb tail fat thoroughly. Remove tough sinew and finely chop them separately with a sharp cleaver; combine until the fat is evenly distributed. If necessary, use a coarse meat grinder, but do not puree the meat.

Add the pul biber and salt. Knead with your hands for 4–5 minutes until cohesive and tacky. Divide the mixture into four equal portions of approximately 225 g. Cover and refrigerate for 30 minutes.

Prepare a charcoal grill with hot, evenly glowing embers and no active flames. Lightly moisten your hands with cold water. Press each meat portion evenly around a wide flat skewer, forming a kebab roughly 25–30 cm long, about 2 cm thick. Seal the ends firmly against the skewer.

Grill over the embers for approximately 10–15 minutes, turning every 2–3 minutes so the meat browns evenly without burning. Move the skewers away from flare-ups. Cook the minced lamb thoroughly; use a food thermometer to check for at least 71°C (160°F) at the center.

Grill the tomato halves and green peppers until softened and lightly charred. Toss the sliced red onion with sumac and parsley.

Slide the kebabs from the skewers onto warmed lavash. Serve immediately with the grilled vegetables and sumac onions.