Another one of Grandma’s treats, we always called them “gnawkey” — so when I first encountered them in a restaurant where they said “G-No-Key” there was a bit of confusion!
Several years ago, my brother and I took a cooking and language course in Florence, and one of the dishes we learned to make was gnudi – similar but with spinach and ricotta instead of potato, and rolled into little balls. Like ravioli but without the pasta shell.
I make them with sweet potato, as well, and even with beets.
The recipe grandma used is somewhere, but it’s pretty basic — mashed potatoes, flour, egg, salt, pepper, nutmeg. Make into a pasta like dough that you can roll into a rope and then cut off little chunks. Traditionally we rolled them off the back of a fork for the ridges, but recently I got a wooden block and dowel that produce a nice even texture. Some people just chop them into little blocks.