Test cook Bridget Lancaster shows host Christopher Kimball how to make foolproof Gnocchi at Home. Next, gadget guru Lisa McManus reveals her top pick for rotary graters. Then, Chris discusses with science expert Guy Crosby the science of soil and its effect on the taste of tomatoes. And finally, test cook Yvonne Ruperti shows Chris how to make an Italian recipe for bread and tomato salad, Panzanella.