To make the Toppings for the Shawarma Sandwich:
1. In a bowl, combine the onion, parsley, sumac and salt. Toss to mix and keep aside.
2. To make the sauce, in a bowl combine all the ingredients, stir well and keep aside.
3. On pita bread, spoon the cooked shawarma, top with the onions, tomatoes and sauce.
4. Roll and serve.
Watch this excellent video for the most popular Middle Eastern dish called Shawarma. The recipe is well explained and wonderfully presented. This is one dish that you would really enjoy with pita bread, tabbouleh, fattoush, taboon bread. Try out this tender, juicy beef recipe and enjoy! It is the best sandwich you've ever had!