Migration is a prism. Land is a lens. Identity has no one truth, and fewer answers. A taxi toxen, a suitcase, a vanished prime minister, a slur on a chalkboard, a sack-lunch meal. All these appear distilled by Ethiopian American (by way of Europe) writer and lawyer Meron Hadero in her short story collection, “A Down Home Meal for These Difficult Times,” published June 28 by Restless Books.