Step 1

For the chicken shawarma: Combine the yogurt, olive oil, garlic and lemon juice in a large bowl. Add the cumin, coriander, paprika, onion powder, allspice, cardamom, cinnamon, turmeric and 2 teaspoons salt and mix to combine.

Step 2

Add the chicken and toss to make sure every piece is fully coated and smothered in the marinade. Cover and refrigerate for at least 4 hours and up to 8 hours. Soak 3 wooden skewers in water for 30 minutes.

Step 3

For the toum: Meanwhile, slice the garlic cloves in half and remove any green sprouts. Place the garlic and 1/2 teaspoon salt in a food processor and blend until it becomes a paste, scraping down the bowl as needed.

Step 4

With the food processor running, pour in 1/2 cup of the oil in a very thin stream; this should take about 2 minutes. Stop to scrape down the bowl. Turn on the processor again and stream in the lemon juice, then stream in another 1/2 cup of the oil very slowly. Add 1 tablespoon of the ice water and pulse to combine. Add another 1/2 cup of the oil, then the remaining 1 tablespoon ice water. Then add the remaining 1/4 to 1/2 cup oil until creamy and fully emulsified. The whole process should take about 20 minutes. The toum will keep, in an airtight container in the refrigerator, for up to 2 months. Makes about 2 cups.

Step 5

Preheat an outdoor grill to medium high and set it up for both direct and indirect heat. (For a gas grill, leave one or two burners on low or off; for a charcoal grill, bank the coals on one side of the grill.)

Step 6

For serving: Cut the onion in half and place one half cut-side down on a cutting board. Insert the wooden skewers in the onion, blunt side in. The skewers should be spaced apart equally from each other to form a triangle.

Step 7

Thread the pieces of marinated chicken onto all 3 skewers on top of each other with no space between them. When all the chicken pieces are threaded, top the skewers with the other half of the onion.

Step 8

Place the shawarma on the direct-heat side of the grill and cook, rotating every 3 to 4 minutes using a pair of sturdy tongs, until you achieve nice grill marks, 10 to 12 minutes.

Step 9

Move the shawarma to the indirect heat side of the grill, cover and cook, turning occasionally so it cooks evenly on all sides, until the meat feels firm to the touch and the internal temperature reaches 160°F, 30 to 40 minutes.

Step 10

Transfer the shawarma to a cutting board. Cover the with a piece of aluminum foil and let it rest for 5 minutes. Uncover and hold the shawarma upright on a sturdy cutting board. Cut the chicken into strips from the top to the bottom of the stack using a sharp knife.

Step 11

Spread a lavash all over with toum. Place some lettuce, onions with sumac, tomatoes and pickles on the lavash and add the sliced shawarma and some French fries. Wrap tightly and serve.