Lightly grease an 8 x 4-inch (or 9 x 5-inch) loaf pan with olive oil. Line with a long enough piece of parchment paper so the wings overlay the long ends.

Preheat the oven to 200 F, then turn it off once preheated.

Whisk together the flours, arrowroot, seeds, yeast, psyllium husk, and salt in a mixer bowl (you can just use a fork or a handheld whisk). Attach the dough hook, add the eggs, onion, olive oil, and honey, then mix on medium-low until the dough is wet and crumbly.

With the mixer still running, drizzle in the water a little at a time, until the mixture forms a thick, spreadable batter.

Transfer the dough to the prepared loaf pan, smoothing out the surface with a small spatula. Lightly grease a piece of plastic wrap, then use it to loosely cover the loaf pan. Place in the pre-warmed (but now off) oven, such that the dough rises enough to touch the plastic wrap. Remove from the oven and set aside.

With the oven rack in the center, preheat the oven to 350 F. Bake the loaf for 40 - 50 minutes, until golden brown on top. A toothpick should come out clean and the surface of the bread ought to sound hollow when tapped.

Let the bread cool completely before serving, unless you're planning to eat it all immediately.

Store in the refrigerator or slice and freeze for up to 1 month.