Ever since Franko posted his semolina filone I've been wanting to try it.   But I didn't want to follow Maggie Glezer's directions (recipe on p. 124 of Artisan Bread) completely since I wanted to adapt it to use a starter instead of a Poolish.    I also didn't have access to fine durum flour - just the big bag of Atta that I hauled home last week.   I have made a few tries at it - today's was my third.    It is the sourest bread I have made recently, with no change to my starter, so I assume it is a function of the fermentation of the durum.   The hardest part seemed to be to get proper opening of the scores.   I think I finally got it.   It wasn't any one thing - just getting a hang of the dough and making small changes to the formula.   The difference in flours meant that Franko's experience - particularly how much water required - didn't match mine.  

Perfect for an afternoon snack.

Formula - with 66% hydration starter 97% white, 3% rye.

Mix all but salt.   Autolyze for 30 minutes.  Add salt.   Bulk Ferment for 3 hours with 2 stretch and folds.   (I didn't do mine evenly because of outages.)   Shape and dust with flour.   Place seam side up in couche.   Proof for 50 minutes.   Spritz with water and sprinkle sesame seeds.   Score down center flat to counter.   Bake at 400F for 20 minutes with steam, 25 minutes without.