I baked this today.....it's a hybrid recipe of my own......a few months ago it was a sourdough Poilane....the formula has evolved to a  sourdough firm starter, with instant yeast 4 pound monster loaded with sunflower seeds, walnuts, flax seed, rainsins, and dried apricots.  I added the instant yeast because the seeds, nuts, dried fruit, and whole wheat flour make the dough heavy......