Knishes can be purchased from street vendors in urban areas with a large Jewish population, sometimes at a hot dog stand or from a butcher shop. It was made popular in North America by Central and Eastern European Jewish immigrants from the Pale of Settlement (mainly from present-day Belarus, Poland, Lithuania and Ukraine).
In most Central and Eastern European traditional versions, the filling is made entirely of mashed potato, ground meat, sauerkraut, onions, kasha (buckwheat groats), or cheese. Other varieties of fillings include sweet potatoes, black beans, fruit, broccoli, tofu, or spinach.
Knishes may be round, rectangular, or square. They may be entirely covered in dough or some of the filling may peek out of the top. Sizes range from those that can be eaten in a single bite hors d'oeuvre to sandwich-sized.
Eastern European Jewish immigrants who arrived sometime around 1900 brought knishes to North America. Knish (קניש) is a Yiddish word that was derived from the Ukrainian knysh (книш) and Polish knysz. The first knish bakery in America was founded in New York in 1910." Generally recognized as a food made popular in New York by Jewish immigrants in the early 1900s, the United States underwent a knish renaissance in the 2000s driven by knish specialty establishments such as the Knish Shop in Baltimore, Maryland, Buffalo and Bergen in Washington, DC, or My Mother's Knish, in Westlake Village, California.
Many culinary traditions feature similar baked, grilled, or fried dough-covered snacks (see list of dumplings), including the Cornish pasty, the Scottish Bridie, the Jamaican patty, the Spanish and Latin American empanada, the Middle Eastern fatayer, the Portuguese rissol, the Italian calzone, the Central and South Asian samosa, the Texan klobasnek, the Czech kolache, the Romanian placinta, the Russian and Ukrainian pirog, pirozhki and vatrushka, the Tatar peremech, the Russian-German bierock, and the Southeast Asian curry puff.