Thursday is gnocchi day in Rome and, I believe, elsewhere in Italy. Keeping up with the old custom, last night at our house we had potato gnocchi with that most classic and sprightly of summer sauces, pesto.
Here's how to make gnocchi from scratch: Boil (or steam) Russet or other mealy potatoes with their jackets on until quite tender. Drain, run cold water over them, and as soon as they are cool enough to handle, pass them through a food mill or potato ricer into a large bowl. Using a wooden spoon or spatula, add a pinch of salt, an egg or egg yolk (optional) and enough flour to make a smooth, pliable dough.
Knead the dough very briefly into a ball (not too much or they will become gummy!) on a lightly floured spianatoia (board for making pasta) or other surface. Then break off a handful of the dough and roll that with both hands until you have a 'cord' about the thickness of your thumb. Cut this cord into short lengths. Take each resulting gnocco and flip it with your index finger against the inside of a fork (or if you have one, a special rigagnocchi, or 'gnocchi paddle', which you can find in some speciality food shops). This will cause the gnocchi to take on a concave shape with ridges on the outside, which will 'catch' any sauce you put on them.
Place your gnocchi on a lightly floured baking sheet as you make them. Cook them in a lightly boiling well-salted water. They are done just as soon as they rise to the surface of the water, vengono a galla, as they say in Italian (see photo below). Transfer to a bowl and then dress them with pesto (see my post on trenette al pesto for the recipe).
For a demonstration of making gnocchi, see this excellent video lesson from my new Foodbuzz friend, Nicoletta Tavella.
NOTE: Making potato gnocchi is simple and yet rather tricky. It is all too easy for them to come out too stodgy, on the one hand, or so light that they fall apart when you cook them, on the other. The key is the ratio of potato to flour. The more flour you add, the more chewy your end product will be. Most people like light, fluffy gnocchi--the 'al dente' concept does not apply to gnocchi--so the less flour you add to the dough, the better. But if you add too little, the gnocchi will fall apart when you boil them. (It is a good precaution, especially if you are early into your gnocchi-making career. to make a single gnocco and boil it to test it out. If it stays together, then continue.) For 4 people, 500g (1 lb.) of potato and 125g (1/4 lb.) of flour usually works well. But you can't depend on exact measurements. You need to add enough flour to make a workable dough, and that will depend on how 'wet' your potato is--which is why it's important to boil your potatoes with their skins on or, even better, steam them with their skins on. This will minimize the moisture in the potato and you'll need less flour.
The choice of potato is very important. You want a mealy, white-fleshed potato like Russets--the kind you would use for mashed or baked potatoes, not the firm, yellow-fleshed kind for potato salad or a gratin. Otherwise, your gnocchi will come out as chewy as gummy bears...
One key variation is whether to add egg or not. I usually do add a small amount of egg (1 for the measurements given above, just the yolk for a smaller batch). Adding a bit of egg makes gnocchi making a lot easier. Some people think that this tends to make the gnocchi too firm, but I find the opposite to be true so long as you only add a small amount, as this actually reduces the amount of flour you need to make a workable dough, and the egg will help bind the ingredients without resort to excess flour. But most Italian recipes call only for potato and flour, so try both methods and see which gives you the more agreeable results.
Some people add some aromatic herbs to their potato gnocchi--parsley, basil, sage, even rosemary. I've never tried this, but if you like, try it and let us know how you like it!
