Preheat oven to 350°F.
Combine Almond Flour, Psyllium Husk Fibre, Salt, Baking Powder, Baking Soda, and Nutritional Yeast in a suitably sized mixing bowl until well blended.
Add egg whites, and mix until a uniform pasty dough forms.
In a separate dish, mix the vinegar with the boiling water.
Slowly add the hot water to the dough mixture, mixing thoroughly and evenly. The dough may appear quite wet at this stage. Set aside and let dough rest for 2-3 minutes.
Divide the dough into 6 portions. With wet hands, roll the dough into balls, and place on a parchment lined baking tray. You can press the dough balls down to flatten slightly if you desire a flatter shape to the buns.
(Optional) Sprinkle your favorite seeds on top of the buns and gently press them down into the top of the bun to ensure they stick.
Bake on lowest rack position for 40-50 minutes, or until browned and cooked. The buns will sound hollow when tapped when they are fully cooked.
Remove from oven and let cool completely.