A few years ago, the editor of a food magazine called and said he was writing an article on pletzel, which he called “Jewish focaccia.” I thought this was a bit of a stretch—but not entirely. I love it and was delighted recently to show my son David how to make it.Bialystoken tzible pletzel kuchen is originally from Bialystok in northeast Poland. Many years ago, the Yiddish Film Archives sent me a clip from the 1930s of a woman proudly holding a freshly baked pie-shaped flatbread topped with onions and poppy seeds. I have never forgotten her or her bread.Called “onion board” by many immigrants to New York, pletzel is made in this country with leftover sweet challah and sometimes with the stiffer bialy dough. Rolled out, then sprinkled with lots of onions and poppy seeds, it is a perfect snack food, even taking the place of pizza for football games or as a main dish to feed hungry people today, just as it was many years ago in Eastern Europe.