Combine oats, brown sugar, butter, salt, 1/2 up of flour, and--if you choose--the flax and wheat germ.
Add two cups of boiling water and mix well.
Allow to cool, to around 98 degrees. When you dip a finger in and it feels only a little warm, you are good to go.
While that cools, add 1 packet (2 1/4 tsp) of yeast to 1/2 cup of warm water. Allow it to dissolve.
Mix the yeast in with the rest of the batter.
If adding an egg, mix that in now.
If using a stand mixer, pour all of that in the mixer with the dough hook attached.
Turn the mixer on low.
Add the flour one cup at a time.
Allow the dough to mix for 5-10 minutes, until it is supple and elastic. You may need to scrape down the sides of the bowl as it mixes.
Remove the dough from the mixer and do a quick knead, shape it into a ball.
Grease a bowl that is at least double the size of your dough ball. Place the dough in the bowl and cover with a damp towel.
Allow to rise for one hour or until doubled.
While the dough is rising, grease or oil a loaf pan.
While the dough is on its second rise, pre-heat your oven to 350 degrees F.
Place the dough in a pan and allow it to rise for another hour or until doubled again. (If you doubled the recipe, you'll have enough to shape two loaves and also make a small batch of rolls, sweet or savory.)
Place doubled dough in the oven and bake for 35-45 minutes.
The crust will be a dark golden brown and sound hollow if you knock on it.
After taking out of the oven be sure to cool your loaf on a wire rack. Do not leave it in the pans.
Allow to cool (if you can stand it) before you slice it up.