1) OK, first step: you need about 2 cups (14 ounces) mashed potatoes, or 14 ounces of riced potatoes (baked potato put through a potato ricer). We made gnocchi using both fresh and instant potatoes. To use fresh, we baked 2 medium-large baking potatoes (8 to 10 ounces each), then peeled them and put them through a potato ricer. For instant, we used 1 1/3 cups (3 ounces) instant potato flakes mixed with 1 1/3 cups (10 5/8 ounces) boiling water to yield a scant 2 cups lightly packed mashed potatoes. The difference in the gnocchi's flavor was indiscernible; so go ahead and use instant potatoes if you like. The point is, you want about 14 ounces of mashed or riced potato, however you get there.
2) Mix the potato with the eggs and salt, then stir in the flour to make a soft dough.
3) Prepare a clean work surface by sprinkling it sparingly with flour; we like to use a silicone kneading mat. Knead the dough a few times to smooth it out, then divide it into eight pieces.
4) Roll each piece of dough into a long rope about the width of your thumb; they'll be about 20" to 24" long. Use a pair of scissors to snip the ropes into ½" to ¾" pieces. Place the pieces on a piece of parchment or waxed paper lightly coated with flour.
5) The traditional and best way to shape gnocchi is with a ridged gnocchi board. Place the bottom of the board on a firm surface, tilt it at about a 45° angle, and pick up one piece of dough. Use your thumb to roll it along the board away from you, for about ¾"; it'll curl up over your thumb, forming a little pocket. Once it's curled over your thumb, toss it onto the prepared parchment. Repeat with all the pieces of dough, placing them back onto the flour-dusted parchment, and giving the pan an occasional shake to roll the shaped gnocchi around in the flour.
6) If you don't have a board, use a fork, turned upside down. The fork won't work quite as well; it's slippery compared to the board, and won't make as many ridges in the gnocchi. But however you get there, you're trying to get ridges into one side of the gnocchi, while a pocket forms on the underside. This is a difficult process to explain, but very easy (and quick) to do. Just practice with a few pieces of dough, and you'll find yourself snapping off shaped gnocchi in less than a second.
7) Once all the gnocchi are shaped, cook them right away, or dust with flour, cover with a kitchen towel, and let rest at room temperature for up to several hours. You can also wrap them tightly (in a single layer), and freeze for up to several months.
8) Sometime before serving the gnocchi, make the parsley pesto. Place all of the ingredients into a food processor, and process until well combined. Don't let it become a paste; it should be a tiny bit chunky.
9) To cook the gnocchi, bring a large, wide pot of water to a boil; a deep sauté pan works well. Add 1/2 teaspoon salt to the water. Drop as many gnocchi into the boiling water as will fit without crowding; this should be about half the recipe, if you have a 12" wide pan.
10) Cook the gnocchi for about 4 minutes; they'll take about 2 minutes to float to the surface of the water, and should cook for about 2 minutes once they've surfaced.
11) Remove the gnocchi from the water with a strainer or slotted spoon; or turn out into a colander. If you're not going to serve immediately, toss with a bit of olive oil, cool, cover, and refrigerate for up to 24 hours. To reheat, dip in boiling water for about 20 seconds.
12) To serve with parsley pesto, stir in sufficient pesto to coat the gnocchi. You won't need all the pesto; the remainder will stay good in the refrigerator for a couple of weeks. Enjoy it on crackers or crusty bread; stir it into olive oil and vinegar for a tasty vinaigrette; or spoon over cooked vegetables. Freeze for longer storage.
Yield: about 160 to 200 gnocchi, about 5 cups cooked, 4 to 6 main-dish servings, depending on appetites; or a greater number of appetizer servings.