Thomas Keller's The French Laundry cookbook but Leather was also a pretty creative guy and may have come up with this method on his own.
As with most things, I have over the intervening years tweeked this a bit. Making gnocchi is something I love to teach Sous Chefs and cooks. Adam Jones and Chris Chandler both learned this method at Halyards in Georgia, and I hope they are passing it along to the folks who work with them now. After I left Halyards I saw that Adam had gnocchi on the menu in a style that was close to what we had done when I was Chef. It was gratifying to know that he had thought enough of those dishes to expand on them and add his own style. He never met Leather as far as I know, but has benefited from that original lesson all the same. Cooking is like that. I once did a stage at the Cherokee Town and Country Club in ATL. I still do a Chicken Terrine that I saw there on that one night. It was one of the coolest things ever and I will pull it out now and again.
So a gnocchi is a potato dumpling. It sounds, and is I imagine Italian. One thing to keep in mind is that potatoes did not grow in Europe before the 16th Century. Like so many things that are ingrained in our Culinary vocabulary the potato is native to the Americas. To the Andes to be more specific. Anyway, leave it to the Europeans to find a really cool application for produce they stole from people they violently conquered.
The best gnocchi are pillow light and yet still dense enought that you can handle them.In our method the potato is baked not boiled. What we do is stab some holes into the potato with a sharp knife, rub it with olive oil, coat liberally with salt, Kosher that is. We will then bake or roast (in reality for most things in the kitchen we say roast. Generally speaking I would say that we "Bake" pastry, and "Roast" things that are savory. There is however little difference between the two) the potatoes on a bed of kosher salt. The holes, the salt and the dry cooking method are all designed to draw moisture out of the potato. Less moisture equals less flour, less flour equals lighter gnnochi.
The next step is to rub the potato through a tamis. What is a tamis- well imagine that you have a round metal or bamboo frame with a window screen tight across one side and there you have it. I prefer to use a tamis for this. You develop less gluten in the potato and end up with a very fine grain of potato and no lumps.
So after you have rubbed your potatoes through the tamis, which you should do when they are hot right out of the oven by the way, you give them a brief chop with a big knife to sort of spread them about on your cutting board or if you are lucky your really think wooden work table. In this next part I am again outside the norm on this adventure. I am going to season and garnish (think truffle or herbs or cheese) at this point and then ever so lightly dust the surface of the potato with flour. How much flour you ask- my pat, trite answer to this is always "enough but not to much". Do this twenty times and you will no longer ask the question. One piece of advice would be that you can add more flour but it is really hard to get it out of the potatoes.
dough scraper for this since it is actually the perfect tool for the job. What you want to do is cut the flour into the potato. After you have cut in the flour we are going to add a small amount of egg yolks. when I was making these I used ten potatoes, maybe 2 to 3 cups of flour and 4 oz of yolks. It made 150 gnocchi.
Use the dough scraper to again "cut" the yolks into the potato and then use it to gather the potato into a shaggy pile. Take a moment to clean the are up a bit. Wash your hands and dry them well, I would also then dust your hands in flour so they are nice and dry. Sprinkle the potato with flour and ever so gently begin to knead the dough. It is not bread so you don't need to go at it with all your pent up gusto. We are gently bringing everything together. And No you cannot use a mixer for this, don't be so lazy you need to develop these skills.
So once you have a nice delicate little ball you will need again to clean up a bit, go wash all the floury potatoey mess off your hands. Before you make the gnocchi go set up your pan for cooking. you can see what I did above was to line the little beauties up in a perforated hotel pan (I think this may be one of the part where I deviated from what I learned from Leather. This is however one of my favorite parts. Take into account that I am making hundreds of these little dumplings) I also put a hotel pan full of water on the fire as we say before I make the gnocchi so that when I am done I can cook them off, multi-tasking.
To make the gnocchi I cut off some dough roll it in a log, by lightly pressing the dough against the board with the palms of my hands (this is for sure a departure from Leather's way. He would put the dough in a piping bag and squeeze out perfectly round logs. I stopped doing that over a lack of a piping bag, a desire to have one less thing to clean up and because it is really impressive when you can roll out a perfectly shaped log with your hands) . Then I cut the little suckers to size and give them a little pinch (I saw this I think in the first Charlie Trotter Cookbook or it could have been the green one). No I don't think you need to press them on a for, which was done to capture the sauce. I think the fork thing looks cool but by the time you blanch and saute the grooves are shot and it makes the whole process take twice as long so I dropped it.
Any way then I drop the pan into boiling water, turn the heat down a bit and wait for them to float (sometimes they stick and need a bit of encouragement to float, when that happens I use a spatuala). I drain them and pop them into the walkin to cool down.
The beef is braised, the sauce has been strained a few times through a chinoise, the mushrooms are roasted the asparagus blanched and it is only a matter of bringing the thing together.
Thanks Columbus, Christian