Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, whisk together the almond flour, psyllium husk powder, baking powder, and sea salt.

Incorporate the egg whites and apple cider vinegar into the dry mixture until a thick paste forms.

Pour the boiling water into the bowl and beat with a hand mixer for 30 to 45 seconds until the dough becomes firm and moist.

Moisen hands with water and divide the dough into 6 equal portions, shaping them into smooth balls.

Arrange the balls on the baking sheet and sprinkle with sesame seeds, pressing them lightly into the dough.

Bake on the lower oven rack for 50 to 60 minutes until the buns are firm and sound hollow when tapped on the bottom.

Transfer to a wire rack and allow to cool completely before slicing to ensure the interior sets properly.