fresh vegetables of your choice(tomatoes, cucumber, avocado work well)
Mix all the marinade ingredients together then pour over the chicken and allow to marinate for 30 mins - 1 hour.
In the meantime, mix together the dry ingredients for the flatbread then add the yogurt and oil. Add the milk, a little at a time, and mix until a rough dough starts to form. You might not need all the milk. Turn the dough out onto a floured surface and knead until it just comes together in a smooth ball. Cover in plastic wrap and allow to rest at room temperature for 30 minutes.
Pre-heat the oven to 240ºC/460ºF (or as hot as your oven goes) with the top element/grill to caramelize the skin on the chicken.
Place the chicken in a baking dish/baking sheet in a single layer then place in the oven. Allow the chicken to bake/grill until fully cooked with the skin crisp and caramelized.
While the chicken is baking, roll tennis-sized balls of dough out onto a floured surface (to around ½cm thick) and cook in a hot pan until golden and bubbling then flip and cook for another minute or two on the other side. Remove from the pan, brush with melted butter (optional) and keep wrapped in foil.
Make the sauce by combining all the ingredients and mixing well.
When the chicken is cooked, remove from the oven and slice.
Serve the chicken shawarma in the flatbread with vegetables and pickles of your choice drizzled with the garlic sauce.