Place buckwheat in a large bowl and pour in enough boiling water to cover the buckwheat by a couple of inches. Let stand for 20 minutes, then drain, rinse with cold water, and let drain well.

Preheat the over to 325° Fahrenheit. Line a 9x5-inch bread pan with parchment paper and set aside.

Add the drained buckwheat to a food processor or blender, along with the water, flaxseed, sugar, psyllium husks, baking powder, cinnamon, cardamom, orange zest, and salt.

Process in short bursts until the buckwheat is broken down and almost smooth. You don’t want it to be completely blended smooth.

Transfer the mixture to the prepared pan and smooth the top with a spoon or spatula. Bake in the preheated oven for 90-95 minutes, until a toothpick inserted in the center of the loaf comes out clean.

Let the bread cool in the pan for 15 minutes before using the overhanging parchment paper to gently lift it out. Remove the parchment paper and let the loaf cool completely on a cooling rack before slicing.

Store the cooled bread in an airtight container in the fridge for up to a week or in the freezer for up to 6 months.