In a blender, finely grind the amaranth, quinoa, flaxseed and chia with the spelt flour. Scrape the sides of the container several times while grinding.
In a stand mixer fitted with the dough hook, combine the spelt flour mixture with the all-purpose flour, wheat flour, yeast and salt. Add the water and knead for 5 minutes. The dough will be very sticky. Cover with plastic wrap and let rise in a warm, humid place for 2 hours or until the dough has doubled in volume.
Place the mixed grains and seeds in a large bowl.
Knead the dough by folding it onto itself several times for 30 seconds. Place it in the bowl with the grains and seeds and turn to coat. Transfer to a 4 x 10-inch (10 x 25 cm), 6-cup (1.5 litre) loaf pan. Cover with plastic wrap and let rise in a warm, humid place for 30 minutes or until the dough has risen above the edge of the pan.
With the rack in the middle position, preheat the oven to 425°F (220°C).
Bake for 50 minutes. Let cool on a wire rack before unmoulding.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.