The 'Top Chef' judge and Craft restaurateur explains how to learn to make the potato dumplings. (Expect to not get it right the first time.)
Video: Listen as Chef John Keenan shows how to make gnocchi.
My general rule of thumb when it comes to cooking is that the fewer ingredients a dish contains, the harder it is to do right. Bread is a classic example. It contains in its simplest form just flour, water, salt and yeast, but making a great loaf can take a person years to master. The tiniest variation in the temperature of the proofing environment, the hydration level of the dough or the intensity of your kneading can make or break the whole project. Gnocchi, a simple dumpling made from potatoes, flour and egg yolk, is no less of a challenge.
We've probably all tasted examples of gnocchi done poorly. They're dense, chewy and bland, little gummy potato pellets that taste of raw flour and, frankly, aren't worth eating. Done right, though, gnocchi are pillowy and tender, and they practically melt in your mouth.
Like many of the best recipes for classic dishes, my gnocchi recipe came from an Italian nonna: The mother of Marco Canora, my original chef de cuisine at Craft, who grew up in the Tuscan town of Lucca. The recipe hasn't changed much over the years, and making the gnocchi is still a task that falls to only the most senior cooks in each of my kitchens. It can take them months or years of watching and helping before they get good enough to do it on their own. Here, I'm going to try my best to distill in a few paragraphs what I teach my cooks about the keys to great gnocchi.
First, a little history. Gnocchi, a.k.a. potato pasta or "potato plugs," as we call them in the kitchen at Craft, originated in the 1300s as dumplings made of flour or bread crumbs. When the potato arrived on the scene in Europe in the 16th century, gnocchi quickly evolved into a primarily potato-based foodstuff. These days they are classified as a sort of pasta and typically served with a light sauce such as pesto, beurre fondue or a thin marinara to complement their delicate texture.
Now for the technique. Gnocchi dough is made by combining roasted potato, flour for absorbing moisture and providing gluten, and a little bit of egg yolk to add richness and help bind the dough together. The general principle is that you want to use as much potato and as little of everything else as possible to still end up with a cohesive dough.
Moisture in the potatoes is the enemy because it means having to add more flour. So you want to start out with potatoes with lower water and higher starch content — Idaho or other russet baking potatoes work well, and Yukon Gold or other sweet, waxy varieties do not. Potatoes get starchier as they age, so older potatoes are actually preferable here.
You want to encourage the potatoes to release as much of their moisture as possible during the cooking process. Prick the skins all over with a fork before baking them; slice them open immediately out of the oven; and — trying your best not to burn yourself — scoop the steaming hot contents of the potato into a fine ricer or food mill as soon as possible. These three things will help steam escape.
Once you've riced the potatoes and turned them out onto a clean work surface, it's time to make the dough. Working a pastry bench scraper in chopping motions, distribute the potato evenly across your work surface, then drizzle that with your beaten egg yolk. Add pepper.
The flour that we use for gnocchi is what's called doppio zero in Italy — "00 flour" to us Americans — which is very finely milled and soft as talcum powder. It leads to a smoother, more supple, malleable dough, which is why it's often used in pizza dough and fresh egg pastas.
Exactly how much flour to use is where judgment comes into play. It all depends on the water content of the riced potatoes, which varies significantly between batches. The dough should be about the stiffness of pizza dough; if you don't know what pizza dough feels like, squeeze your earlobe gently between two fingers. The gnocchi dough should hold together but still be moist. Ed Crochet, the sous-chef who makes the gnocchi every day at Craft in New York, can measure out flour by sight and knows instantly upon touching the dough whether it needs more.
Once you've blanketed your potatoes in flour, use a chopping motion with your pastry scraper again to mix the potato and flour together into a coarse meal. Then, still using your hands and the pastry scraper, gather it up into a ball and begin folding the dough. Fold in more flour for the first couple of folds, and turn the dough over eight to 10 times total. The goal is to incorporate the flour as thoroughly as possible without working the dough too much, which will make it gummy. After you're done folding, form the dough into a log, smacking it hard on all sides for about a minute to get it as dense as possible and move any air bubbles out.
Working with one section at a time, roll the dough into a log about 1/2-inch thick. It can be hard to control the dough when rolled as thin as this, but if you leave it any thicker, the outside of each dumpling will overcook before the center is done. Keep in mind that you need to work through the rolling process relatively fast, because the longer the dough sits, the softer it gets and the harder it is to work.
At this stage of the game, many people like to shape their potato dumplings using a grooved gnocchi board, the tines of a fork or a thumbprint. The claim is that flattening them slightly and dimpling them allows them to cook through more evenly. That logic doesn't make any sense to me, and our gnocchi are so delicate that fiddling with them any more than necessary could ruin them. I like the look of plain, cylindrical gnocchi just fine (which happens to be the traditional shape of pastry-based gnocchi parisienne), so I'm happy to leave them as is and save myself the extra step. So once you've rolled out your first log of dough to the proper thickness, use your pastry cutter to divide it into 1-inch-long pieces. And there's your gnocchi.
The moment of truth arrives when you cook the gnocchi. You should do so in boiling water that's as salty as seawater; this is where the gnocchi will pick up all its necessary seasoning. As soon as each potato dumpling bobs to the surface, scoop it up and transfer it to an ice water bath so that it stops cooking immediately. If the gnocchi fall apart or appear to be fraying at the edges, it can mean one of two things: You let them cook for too long or, even worse, you didn't combine the potato and flour into true dough. In the latter case, it's back to square one.
Last, and most important: Be prepared that your gnocchi may not come out perfect the first time. In fact, they probably won't. Keep trying. Gnocchi take patience, but they're worth it.
Colicchio is the chef-owner of the Craft family of restaurants and is the host and head judge of the Bravo television series "Top Chef." He was named national chef of the year by the James Beard Foundation in 2010.