Preheat the oven to 350 degrees. Lightly grease 6 four-inch hamburger bun molds or line a large baking sheet. Set aside. Grind the psyllium husk until it is half its volume. Pour the ground husk in a large mixing bowl. Sift the dry ingredients into the bowl with the ground husk until there are no lumps.
Stir the eggs, olive oil, butter and vinegar into the dry ingredients until fully combined. Add the hot water and stir for at least 1 minutes until combined and a smooth dough has formed. Scrape down the sides of the bowl and push the dough to the center of the bowl. Knead the dough in the bowl for 2 minutes until the dough forms a smooth ball.
Let the dough sit at room temperature for 15 minutes to absorb the excess moisture. After 15 minutes dough should still be slightly moist. Divide the dough into 6 equal portions. Roll each portion into a smooth ball and place in the prepared molds or baking sheet. Use the palm of the hand and slightly flatten the top of each of the dough ball to form a bun shape.
Melt 1 TBS butter until fully melted. In a small bowl stir together all the topping ingredients until fully combined. Brush the tops of the shaped buns with the melted butter. Sprinkle the cheese herb topping evenly over the melted butter. Bake in the preheated oven for 30 to 35 minutes until golden and the cheese is lightly browned
Remove the buns from the oven. Allow to cool in the pan for 20 minutes or until firm. Once firm transfer them to a wire rack and allow to cool for at least 1 hour before slicing. Once the buns have set, turn the buns on their side. Cut the buns in half to create a top and bottom portion.
Use immediately in any recipe that requires sandwich or hamburger buns.