Number of people
To prepare the marinade: In a bowl, mix yogurt, vinegar, garlic, cardamom, allspice, and lemon juice. Season with salt and black pepper. Mix and gradually add olive oil, one tbsp at the time.
Add beef strips to marinade and refrigerate for at least 8 hours or overnight.
Heat a non-stick pan over medium heat. Take beef strips out of the refrigerator and stir fry for 45 minutes until cooked through. In a bowl, combine red onion, tomato, onion, lettuce leaves sumac and chopped parsley. Add cooked shawarma and mix until combined.
In the middle of a pita loaf, add ¼ quantity of the shawarma mixture. Roll into a sandwich. Repeat step 5 until quantities are finished. Serve with tahini sauce.