Preheat the sheet tray

• Place the sheet tray in the oven and heat on high broil.

Marinate the chicken

• Cut the chicken thighs very thin.
• Add the yogurt, tomato paste, garlic paste, olive oil, lemon juice and shawarma rub.
• Season generously and mix quickly until the chicken is well coated.

Cook the chicken

• Add the beef tallow to the hot sheet tray.
• Spread the chicken in a single layer so it cooks evenly.
• Broil on high until cooked through.

Warm the bread

• Separate the flatbread halves and stack them on top of each other.

Assemble and toast

• Spread a generous amount of mayonnaise on the bread.
• Add the chicken and plenty of pickles.
• Spoon over some of the pan drippings.
• Toast the sandwich and serve.