"This is a flavorful chicken dish, which I first tasted at a little Lebanese restaurant. While normally shawarma is sliced off a rotisserie, it can be made at home with just a few changes. Be warned, it takes a day of prep time. For lunch, serve as a sandwich in warmed flatbread with cucumber sauce, sliced onion, and seeded tomato. For dinner, serve with rice and lentils (for a treat, look up mujadarrah on this site)."
Whisk yogurt, lemon juice, olive oil, tomato paste, garlic, cumin, coriander, salt, pepper, and red pepper flakes together in a bowl. Mix in chicken strips. Cover bowl with plastic wrap and place in the refrigerator to marinate, 8 hours to overnight.
Set oven rack about 6 inches from the heat source and preheat the oven's broiler.
Remove chicken from the bowl and arrange in a single layer on a broiling pan. Discard excess marinade.
Broil chicken, turning once, until juices run clear, about 10 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).