First, prepare the yeast mixture by adding sugar to the warm milk. Then add the yeast and gently mix the mixture. Cover the yeast mixture and set it aside for 10 minutes.
In a bowl, whisk together the flours, baking powder, xanthan gum, and salt. Then make a small hole in the middle and add in the egg, apple cider vinegar, yoghurt, and vegetable oil. Then add the yeast mixture created in step 1.
Using a stand-alone mixer with the paddle attachment or a hand-held mixer, beat the ingredients together at medium speed until combined.
Then, apply vegetable oil to a separate bowl and move the dough to the bowl. Cover the bowl with a damp towel and let the dough rise for 2 hours.
After the dough had risen, divide it into 8 separate sections. Then shape each section into a ball.
Preheat the oven to 180°C and move the rack to the bottom of the oven.
Using a rolling pin, flatten the dough to a 9-inch diameter circle. Ensure that the circle's thickness is no more than 2 mm (See notes below).
Bake the dough on the bottom rack for 7 minutes. Then remove the manakish from the oven and apply the topping (Cheese or Za'atar). Then bake the manakish for another 2 minutes at the bottom rack.