Step 1

In a large bowl, stir together the potato flakes and water. Let stand until cooled to room temperature. Add the egg, flour and salt, then mix with your hands until the ingredients are just incorporated. Lightly dust the counter with flour and turn the dough out onto it. Gently knead until the dough is smooth.

Step 2

Using a rolling pin, roll the dough into a ½-inch-thick rectangle. Cut the dough into ½-inch strips, then, using your hands, roll each strip against the counter into a ½-inch diameter log. Cut each log into 1-inch pieces. If desired, dip the back of the tines of a fork into flour, then gently press into each piece to create a ridged surface.

Step 3

In a large pot, bring 4 quarts salted water to a boil. Add half of the gnocchi, return to a boil and cook, stirring gently and occasionally, until the gnocchi float to the surface. Cook for 1 minute, then use a slotted spoon to transfer the gnocchi to a wire rack. Return the water to a boil and repeat with the remaining gnocchi. Let the gnocchi cool for at least 15 minutes before using.