In a bowl, combine the dry ingredients through salt.Whisk well.
In another bowl, add 2 Tbsp warm water and mix in the yeast and sugar. Let it sit for 2 minutes or until frothy.
Grind or blend the flax seed meal and psyllium husk to make a coarse meal.
In another bowl, well yes, another bowl, mix the flax+psylium with warm hot water. Add in the sweet potato and mix in. Let it sit for 2 minutes.
Combine the wet bowls into the dry or choose any one bowl in which you empty the other 2. Mix well. Knead to make a smooth soft dough. The dough initially will appear dry and then will come together. If you continue kneading it will continue to get sticky. Stop kneading when smooth and soft and just about getting sticky.
Depending on the moisture in the sweet potato puree, you might need a tbsp more oat flour or a few sprinkles of water.
Let the dough sit for 5 minutes.
Flatten the dough on parchment into 1/2 to 3/4 inch thick rectangle.
using a pizza cutter or knife cut the rectangle into cubes.
Place the cubes on parchment lined sheet. Spray water on them and let sit for 10 to 15 minutes.
Prepare the baking soda solution and cornstarch solution from Pretzel recipe here.
Preheat the oven to 450 degrees F / 220ºc.
Brush the pretzels liberally with hot baking soda solution. Let it sit for 2 minutes.
Then brush with hot or warm cornstarch solution.
Sprinkle salt. Place another parchment sheet on top on the entire baking sheet to cover all the pretzels.*Important. else the pretzels will dry out and get hard during baking.
Bake for 12 minutes. Remove top parchment, turn the baking sheet around and bake for 2 minutes. Broil for half to 1 minute if the pretzels have not browned enough.