2Grind onion and garlic into a paste using a food processor.
3Add the onion and garlic paste to a bowl along with ground beef, seasonings (paprika, garlic powder, cumin, dried parsley, coriander, sumac, kosher salt, black pepper), Greek yogurt, tomato paste, and olive oil.
4Mix the ingredients very well.
5Take a handful of the meat mixture (approximately 3/4 cup) and place it between two pieces of parchment paper.
6Roll the meat out thin and as evenly as possible with a rolling pin.
7Roll up the parchment paper with the meat inside and repeat for the remaining meat.
8Bake the rolled meat in the oven for 30 minutes.
9Remove from oven, unroll the parchment paper, and break up the cooked meat.
10Thinly slice red onion using a mandolin for the piyaz salad.
11Add the sliced red onion to a bowl along with sumac, half a lemon, olive oil, and chopped parsley. Toss well.
12For the yogurt tahini sauce, add Greek yogurt, tahini, lemon juice, mashed garlic, cumin, kosher salt, and black pepper to a bowl.
13Whisk the sauce ingredients together well, then taste and adjust seasonings, adding water as needed to thin.
14Prepare roasted vegetables (tomatoes, bell pepper, jalapeno) by drizzling with olive oil and seasoning with salt before roasting.
15Assemble the doner kebab by spreading yogurt tahini sauce on lavash bread, adding the cooked meat, roasted vegetables, piyaz salad, and romaine lettuce.