Mix all the dry ingredients (psyllium husk powder, almond flour, baking powder and sea salt) in a large bowl until well combined.
Bring 1 cup water to a boil.
Add the wet ingredients (apple cider vinegar, egg whites and water) to the dry mixture. Beat with a hand mixer for 30 seconds. DO NOT OVER MIX. The dough resembles a play-doh consistency.
Moisten your hands with olive oil. Shape the dough into 6 separate balls.
Place on a greased baking sheet and top with sesame seeds.
Place a baking paper on the Air Fryer grill pan then carefully place the dough balls. Making sure to keep spaces between them.
Bake in an Air Fryer on a 160°C for 30 mins. It should be done if you hear a hollow sound when tapping the bottom of the bun.
Serve with butter or spread of your choice.