Put the three flours into the bowl of a stand mixer, then add the salt and yeast on opposite sides of the bowl and stir in each with your finger. Keeping the salt away from the yeast is the goal.
Mix in the cooked quinoa, oats, and flax seeds on low speed with the paddle attachment, then pour in the melted butter, molasses, and half of the water and mix until a dry dough forms.
Keep the mixer running on low and gradually trickle in enough water to create a somewhat sticky dough. Depending upon the brands of flour and the humidity, you may not need all the water, or you may need more.
Switch attachments to the dough hook and knead for 4 minutes on medium low, or until the dough passes the windowpane test. This means that a lump of dough can be stretched until it's translucent without tearing.
Form the dough into a ball, lightly coat it in bread flour, and cover tightly with plastic wrap. Leave it to prove in a warm place until it's at least doubled in size, about 1 to 1 ½ hours.