In a food processor or blender, combine the almond flour with coconut flour, xanthan gum, baking powder, and a pinch of sea salt. Pulse to mix well.
Add the apple cider vinegar and pulse again.
Add the egg and the water. Pulse until the dough forms into a sticky ball.
Wrap the dough in plastic wrap and knead through the plastic for a couple of minutes.
Let the dough rest for 10 minutes. Divide the dough into 8 small balls (about 1 inch) and roll out each ball between two sheets of baking paper with a rolling pin until they spread into a 5-inch circle.
Heat a dry pan over medium heat.
Cook the tortillas for about 5 seconds on the first side, flip and cook for 30 seconds on the other side.
Serve warm wrapped in towels or rewarm by heating briefly on both sides for a few seconds to regain their elasticity.