Place the flour, flaxseed, sesame seeds, oat bran, sunflower seeds, dulse flakes or salt, baking soda, and quinoa (or amaranth, millet, or poppy seeds) in a very large mixing bowl. Stir together, then create a well in the center. Pour the beer and buttermilk into the well, and then mix with the handle of a wooden spoon until a thick, wet batter forms. Sprinkle a light layer of flour on top, then turn the dough onto a lightly-floured surface.