Whisk together the dry ingredients (flours, xanthan gum, baking powder, salt) until well combined.Add the egg and egg white and beat gently into the flour to incorporate. The dough will begin to form.Work the dough to allow the flour and xanthan gum to absorb the moisture.Cut the dough in 4 equal parts and press each section out with cling wrap. Watch the video for instructions!Heat a large skillet over medium heat and add oil.Fry each flatbread for about 1 min on each side.Brush with butter (while hot) and garnish with salt and chopped parsley.