In a bowl, mix the yeast, sugar, milk, and water together. Cover the mixture tightly using a plastic wrap or a kitchen towel, and let it sit at room temperature for 10 minutes. The yeast should activate and form bubbles.
In the bowl of a stand-alone mixer, sift the flours, salt, baking powder, and xanthan gum. Using a hand-held whisk, whisk the dry ingredients to combine.
Next, add the olive oil and yeast mixer to the dry ingredients. At medium-low speed, blend the ingredients with the paddle attachment attached for about 3-5 minutes.
Transfer the dough to a greased bowl and cover it with plastic wrap and a damp kitchen towel. Allow the dough to rise for two hours at room temperature.
Once the dough has risen, pre-heat a medium-sized skillet on the stove at high heat.
Then divide the dough into eight equal parts.
Dust the working surface with gluten-free flour to begin shaping the dough. Flatten each dough into a 20-23 cm circle in diameter with a 3 - 4 mm thickness, using a rolling pin. If the dough is too sticky, dust a small amount of gluten-free flour on it.
Lower the heat under the skillet to medium-low. Working with one shaped dough, gently transfer the dough to the skillet using a spatula. After 10-12 seconds, or once tiny bubbles have formed on the dough, flip the dough using a spatula for cooking the other side. Let the other side cook for another 10 seconds. Next, transfer the flatbread to a clean kitchen towel and cover it with the towel.
Keep repeating step 8 until you are out of dough.