If wishes were knishes…they’d all taste delicious.—Variation of old Scottish rhyme Little pastries stuffed with meat, potatoes, and other savory fillings, knishes immigrated to the US with Russian, Polish and Ukrainian Jews in the early 1900s. They soon dominated delis, knisheries and food carts in New York City. This inexpensive snack/meal spread to Kosher delis and restaurants across the country—so what’s not to like? But as Jewish delis have dwindled, so have knishes. Our local Stop and Shop no longer carries them in the deli case. But we don’t kvetch. Thanks to our daughter Claire, we have the best recipe for this nosh that you can find anywhere. Using Science and Laboratory Superpowers, she…