Preheat the oven to 325˚F. Line a baking sheet with parchment paper.
Rinse the buckwheat and millet in a strainer with cold water and drain well. Transfer the grains to a large bowl, and add the pumpkin seeds, coconut flakes, chia seeds, cinnamon and salt.
In a small saucepan, combine the sunflower seed or almond butter, coconut oil, vanilla and honey or stevia. Stir over medium heat until melted and smooth. Pour the wet mixture over the dry ingredients; stir until everything is well coated (if using stevia, give it a taste and add more if desired).
Transfer the granola to the prepared baking sheet. Spread and pat the granola into a 12x9-in rectangle, about ½ inch thick. Bake 15 minutes. Gently stir, using a spatula to flip the granola over (try to keep some chunks intact). Bake an additional 14-15 minutes, or until lightly browned around the edges (if using honey, check at 14 minutes). Give it another gentle stir, then bake 5 minutes longer, or until the granola feels slightly dry (it will continue to dry out as it cools). Remove the pan from the oven, and cool the granola completely.
