Soak the buckwheat in enough water to cover, for at least two hours but not over 8. You just want them to be soft enough to crush with your fingertips. Once they have soaked, rinse well. The buckwheat will be kind of slimy so rinse very well and let drain.
1 ¾ cup buckwheat groats
Meanwhile, combine the psyllium and chia with the water, stirring to combine. Let sit for about 10 minutes until thick.
2 tablespoons psyllium husks*, 2 tablespoons chia seeds, 1 cup water
In a food processor or high-speed blender, add the soaked buckwheat, psyllium gel, oil, baking powder, and salt. Puree until the mixture is sticky and most of the grains have been pureed to a mush. If you are using a blender, you may need to remove it from the base and stir it a couple of times.
3 tablespoons olive oil, 2 teaspoons baking powder, ½ teaspoon sea salt
Scoop the mixture into a parchment-lined loaf pan. Flattening the top with the back of the spoon to make sure it's evenly spread out. Top with seeds if desired. Bake at 160°C (320°F) for 90 minutes.
Seeds for topping
Let the loaf sit for a few minutes before removing from pan. Let cool on a wire rack. Wait until the loaf is entirely cool before slicing. The loaf can be wrapped and stored in the refrigerator for up to a week, or sliced and frozen.