Like 15,000 other Polish immigrants who arrived in Baltimore around the turn of the 20th century, my maternal great-grandparents, Jozef and Michalina Oleszcuk, ended up in the waterfront community of Fell's Point. Two decades later, 70 percent of the neighborhood's storefronts had Polish signs in their windows. Though she died before I was born, my grandmother tells me Michalina kept a larder stuffed with Polish foods. At the butcher on Fleet Street, she bought live ducks, which she used to make a velvety sweet-and-sour soup called czernina. She shopped at stalls in Broadway Market for specialties like krusciki, bow-tie fritters dusted with powdered sugar.