Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.

In the bowl of a stand mixer, using the whisk attachment, mix the coconut flour, potato flour, xanthan gum, baking powder, and salt until blended.

Add the water, shortening, eggs, and vinegar and mix on high speed for a few minutes, until tacky dough has formed.

Oil your hands and divide the dough into 8 to 10 equal portions. Roll each portion between your hands to form a ball, and then usa a well-oiled thumb to create a hole in the center, Make the hole large, because when the sough rises in the oven, the hole will close in quite a bit! Place a shaped bagels on the prepared baking sheet.

In a small bowl, whisk together the egg and tablespoon of water to make the egg wash. paint a little egg wash oven each bagel and then add any toppings, if using. Reserve the leftover egg wash.

Bake the bagels for 50 to 55 minutes, until beautifully golden and firm to touch. Brush them with additional egg wash halfway through baking.

Remove from oven and enjoy! Store in a sealed bag or container, or freeze for another day.