Whisk together the flours, garlic powder, and salt in a medium mixing bowl.
Add the egg and whisk just enough to break it up for blending.
Stir in the milk and whisk until the batter is smooth.
Preheat a nonstick skillet over medium heat. (I set my induction cooktop to 300 F and used a well-seasoned cast iron skillet.) Add a tiny bit of oil.
Pour out enough batter to fill out the shape of one tortilla. Let it cook until it begins to look dry on top. It's okay to lift a little at the edge to check and see that the bottom isn't burning.
When the tortilla is dry on top and starting to brown on the bottom, flip it over to finish cooking on the second side.
Video
Notes
The tortillas can be served immediately or stored in the refrigerator or freezer between layers of parchment paper.