Potato kneidlach are light, fluffy potato dumplings for Passover that are a wonderful gluten-free substitute for matzo balls. I have loved these ever since I first made them for a gluten-free friend in 2005. I based this recipe off of one from The Passover Gourmet by Nira Rousso. My dad e-mailed me Rousso's recipe for potato dumplings a few years ago and I used that as the basis for these. Leftover batter can also be fried into chewy potato pancakes, as well.