Traditionally pastillas are huge labor intensive concoctions. Scaling down the size of pastilla doesn't take a single bit away from it's flavor, but reduces preparation time and effort considerably. If pastilla sounds like bastila to you, that is because that's exactly what it is. As usual, Algerians have a variety of pastilla preparations. If the name sounds Spanish too, well that's because it is a Spanish name. There is an antecedent to this dish in the anonymous thirteenth century Hispano-Muslim Cookbook which describes chicken wrapped in many paper thin sheets of dough. I do have a copy of the anonymous cookbook, but I did not make the connection until I read about it in Clifford Wright's A Mediterranean Feast.