Here's the recipe I use.
500g (about 1 pound 2 ounces) ground lamb
7.5 g Kosher salt
2 teaspoons ground cumin (divided)
2 tablespoons ground sumac (divided)
2 tablespoons ground Urfa pepper flakes (divided)
2 tablespoons ice-cold water
For Serving:
1 red onion, thinly sliced
6 pieces lavash or pita
1 cup picked fresh parsley leaves
2 medium tomatoes, thinly sliced
Pickled sport peppers or pepperoncini
Directions
For the Kebabs: Combine lamb with 7.5 grams (about 2 teaspoons) kosher salt, 1 teaspoon cumin, 2 teaspoons sumac, and 1 tablespoon pepper flakes. Knead by hand or in a stand mixer fitted with a paddle attachment until mixture turns tacky and starts sticking to the side of the bowl. Add water and continue kneading until incorporated. Place in refrigerator and chill well.
Meanwhile, combine remaining teaspoon cumin, 2 teaspoons sumac, remaining tablespoon pepper flakes, and 2 teaspoons salt in a small bowl. Set spice mixture aside. Combine remaining 2 teaspoons sumac and red onions in a medium bowl. Season with salt to taste and set aside.
Using wet hands, divide lamb mixture into 12 even balls. Using wet hands, form each ball into a long, flat kebab around a skewer.
Grill over medium heat (400-450F). Sprinkle remaining spice mix while cooking.
Serve kebabs with warm bread, sumac onions, parsley, tomatoes, and pickled peppers.