1.   Pre-heat your oven to 400 F or 200 C. Line a loaf pan with parchment

2.   To a food processor, add all the dry ingredients: the walnut halves, the coconut flour, whole psyllium husks, the gluten free baking powder, and baking soda. Pulse until your dry ingredients are about the texture of almond meal

3.   Toss this walnut flour into a large mixing bowl, make a well in the center. Then, get your bowl with the egg whites and whisk them well with a fork

4.   Pour the whisked whites into the well in your mixing bowl of dry ingredients

5.   Stir until all the dry ingredients have been incorporated with the egg whites

6.   To the measuring cup of boiling hot water, add the apple cider vinegar and stir. Pour the boiling water and vinegar solution into the mixing bowl. Immediately fold the water with the dry ingredients, just until all the dry ingredients have been combined with the hot water. Do not over fold

7.   Immediately scoop and transfer the dough into your parchment lined loaf pan – you do not need to shape the dough – just gently place and distribute the dough into the pan, but do not compress the dough as you are placing it into the loaf pan

8.   Using your fingers or a spatula, very gently even out the top of the dough. Next, using a pastry brush, coat the melted butter over the entire surface of your dough. OPTIONAL: sprinkle the chopped walnuts over the surface and gently press the pieces to embed them in the dough

9.   The last step is to make several ¼ inch or 6 mm deep – diagonal cuts into the surface of the dough. Place the loaf pan in the middle position of your preheated oven and set your timer for 40 – 45 minutes. When done, test your loaf with a toothpick and if the toothpick is dry, the bread should be done by this point

10.   Turn off the oven heat. Prop the oven door to remain slightly open by placing a rolled-up oven mitt or towel to hold oven door ajar. Leave the bread in the oven to cool for about 20 minutes

11.   Take the pan out of the oven. Lift loaf out of the pan and peel off the parchment paper. Place the loaf onto a cooling rack and let the bread rest until it is completely cooled to room temperature

12.   To serve – just cut the bread into ½ inch or 1.3 cm thick slices. Enjoy!