Add coconut flour, psyllium husk, baking powder and salt in a mixing bowl and combine.
Mix in the eggs. Work quickly, stirring until the powders firm up into a thick dough.
Add a cup of boiling water and mix thoroughly.
Line a baking sheet with parchment paper. Form dough into a flat oval on top of the paper. Use a sharp knife to score diagonal cut through the dough. Sprinkle the top with thyme and additional salt. Thinly slice the onion into rings and arrange evenly over the thyme and salt. Press gently into the dough to stick.
Bake at 350 degrees F for 25-30 minutes. The dough rises about twice as high, with a firm crust once done. If the bread feels spongy to the touch, continue cooking.`
Remove from the oven and cool slightly before cutting; serve warm or cold. Store in the fridge.