In a mixing bowl, combine 3 tablespoons of plain yogurt, half a teaspoon of minced garlic, and one teaspoon each of ground cumin, paprika, white pepper, turmeric, and black pepper. Add salt to taste.
Mix in some olive oil and one tablespoon of tomato puree. Stir until well combined.
Add 900 grams of chicken (a mix of thigh and breast), and marinate thoroughly for at least 30 minutes.
Heat a frying pan and cook the marinated chicken for 10 to 15 minutes or until fully cooked.
Prepare the white sauce by blending one cup of onion with some salt, then adding one cup of hot oil. Once the oil has turned completely white, add lemon juice and blend until fluffy.
Place a small amount of white sauce on the pita bread/tortilla wrap, followed by slices of tomato and large onions.
Add the cooked chicken along with some French fries.
Roll up the wrap to form a shawarma sandwich. For a cleaner presentation, replace the fries with a green salad if desired.
Prepare the white sauce again by mixing 2 tablespoons of toum (or substitute with garlic butter), 4 tablespoons of mayonnaise, and 4 tablespoons of plain yogurt, adding a pinch of dried parsley and lemon juice to taste.
Serve the shawarma immediately or briefly toast it in a pan for extra flavor. Enjoy your delicious homemade shawarma!