To make the marinade:

• Cut each chicken breast in half horizontally, then cut into 1 inch /3cm thick strips.
• Combine together the salt, paprika, cumin powder, cardamom powder, ginger powder, cinnamon powder, grated nutmeg, white pepper, onion powder, garlic powder, coriander powder, cornstarch and crushed garlic.
  
• Add the yogurt, tomato paste, oil, lemon juice, orange juice and vinegar. The lemon, orange and vinegar provide an acid hemp that will tenderize the chicken, whisk together to homogenize.
  
• Add the chicken strips and make sure the chicken pieces are evenly coated in the marinade. Cover with plastic wrap and keep it in the fridge for 24 hours or a minimum of 4 hour
  
• To make the garlic sauce:
• In a saucepan, dissolve cornstarch and water, place on high heat and whisk continuously until the sauce bubbles and totally thickens. Remove from heat and set aside to completely cool down.
• Combine the garlic cloves, ½ cup water, lemon juice and salt. Puree until smooth, the garlic will be more dominant after blending, stop to scrape down the sides of the bowl if needed.
• Add the cornstarch paste to the food processor, and pulse a few times to integrate the garlic mixture with the cornstarch paste.
• Slowly, add the oil, drizzling it in a slow steady stream, while your food processor is running, keep on adding the oil in the same gradual fashion until you used all the oil. It is crucial to add the oil gradually while the food processor is running to help emulsifying the garlic sauce. The end result should be loose and fluffy but not runny. If it is too thick add 3 tablespoons oil and pulse a few times to incorporate the mixture. Taste it to adjust salt to your taste preference.
  
• Preheat oven to 220°C/ 430 °F.
• Add the chicken shawarma and the marinade to a large baking dish. The chicken will absorb some of the marinade, you will have marinade leftover, so add everything and spread everything evenly over the baking dish. Bake in the oven until the chicken is browned and crisp on the edges, for about 50 minutes, for a crispier top, employ the broiler at the very end, for about 2-3 minutes to give everything a little char and browning.
• This step is optional, but recommended! You will receive an irresistible smoky effect, making you think that the shawarma has just came out of a charcoal grill without the struggle of firing up the barbecue at home. You start with a small piece of coal, use natural lump charcoal, and avoid using the ones that have chemicals added to them, light a piece of coal on your stove, keep it until you will be able to see the white ashes appearing on the lit end, then transfer it to a small heat proof cup, put it in the center of the grilled shawarma, add 3 tablespoons of ghee to the charcoal, a dense dark smoke will be emitted. Immediately, cover the cooked shawarma with a lid, and keep it for 1 minute, allowing the flavors to infuse together, this technique gives an intense charcoal barbecue taste to your shawarma. optional!
• To assemble the chicken shawarma wraps: Use Arabic bread, saj bread or other thin flatbread, smear a generous layer of the garlic toum; layer chicken, pickles and fries and some shredded Romain lettuce, wrap it tightly and put it in a panini press or oven to crisp it!