Make Dough

1. Mix together psyllium powder and 260 grams water in small bowl, and set aside to gel. To prevent clumping, make sure you measure out psyllium powder and water separately, and then quickly combine while whisking vigorously. If you combine too slowly without immediately mixing, it will clump, and becomes very difficult to get the lumps out.
2. Combine tapioca starch, potato starch, millet flour, sugar, xanthan gum, baking powder, and salt in a large bowl.
3. Whisk eggs, 120 grams water, oil, yogurt, and sourdough starter in a medium bowl.
4. Add psyllium gel and wet ingredients into dry ingredients, and mix with dough hook until well combined. The dough will still look very wet compared to a "normal" dough, but should hold it's shape.

Form and Proof Loaf

5. Lightly flour board or counter, scrape mixed dough onto board and with as little extra flour as possible, gently fold dough 4-5 times, until you end up with a loaf shape.
6. Place dough into floured banneton to proof. Alternatively, place a linen cloth into bread pan and dust with flour, then put dough into pan. If you have a seam or fold in dough, try to leave this on top. The side that is on top during proofing will become the bottom, we want any imperfections on top.
7. Proof at room temperature for 5-6 hours. Dough should rise to form domed surface, but it doesn't need to double in size, in fact if it has, your dough may be over-proofed.

Bake

8. Invert banneton onto parchment paper that has been trimmed to fit into dutch oven. Then gently lower into dutch oven.
9. Score the top of the loaf with a very sharp knife. You want the cuts to be at least 1/4 inch deep, if not a bit more. If you don't score the loaf deep enough, then it won't rise evenly in the oven.
10. Cover dutch oven, and place into cold oven. Set oven to 450°F and allow to preheat with bread inside. Once oven is up to temperature, bake for 40 minutes with cover on. Then remove lid from dutch oven and reduce temperature to 350°F, bake for additional 30 minutes.
11. Remove loaf from dutch oven and allow to cool on wire rack until cool to the touch. Only once loaf is cool on the outside should you cut into it.°F