Mix together all the grains. Line a tray with layers of kitchen paper folded to about 1 cm (½ in) thick. Moisten the paper and sprinkle the grains over the top. Fill a spray bottle with water and spray the grains every 2 hours for 3 days. Keep the tray covered in a warm, dark place. Once the grains have sprouted and you are ready to serve, heat them in warm duck fat and salt.