Preheat oven to 350F. Line a 9 by 5-inch loaf pan with parchment paper.
Add the yeast and warm water to a small bowl and stir to combine. Let it sit until foamy, about 5 to 10 minutes.
Whisk together the almond flour, psyllium husk powder, baking powder, sunflower seeds, sesame seeds, chia seeds, and salt in a large bowl.
Whisk together the eggs, egg whites, vinegar, liquid stevia, butter, and foamy yeast mixture in a medium bowl.
Stir the egg mixture to the dry ingredients, and then stir in the boiling water.
Transfer the batter to the prepared loaf pan, spreading it out evenly.
Bake until the loaf is golden brown on the top and bottom, and it sounds hollow when you tap the bottom, about 1 hour, 15 minutes. If the loaf starts to look too dark on top before it’s done, cover the top with aluminum foil during the last 15 minutes of baking.
Turn off the oven, leave the foil on top, and let the loaf cool for 30 minutes in the oven.
Remove the loaf and let it cool to room temperature before slicing.