this version of gnocchi is so simple to make and you can use leftover mashed potatoes. They're great with pesto or any other sauce you want to smother them in.
Heat your leftover mashed potatoes, if cold out of the fridge, for about 30 seconds to 1 minute in a bowl in the microwave. They should be slightly warm, but still able to handle. Break the mashed potatoes up with a fork in the bowl.
Have 1 cup of all-purpose flour and a small dish of warm water standing by. Dust a bit of the flour onto your clean counter surface. Then dump the mashed potatoes on top.
Generously dust the potatoes with some more flour and start to knead it with your hands to incorporate it into the mashed potatoes. Do this with a couple tablespoons of flour at a time, adding it in gradually while kneading. The feel you're looking for in the dough is a slightly sticky, bouncy ball of dough. I found it helpful to dip my hands in the warm water and incorporate the last amounts of flour with a bit of moisture to really get it to the right feel. You should have it to a point where you need very little flour on the surface or your hands and it won't stick. As a final step, roll the dough into a smooth ball with little to no cracks in it, on the counter with your hands.
Take a lightly floured knife or dough scraper and cut the ball in half and then each half into a quarter. You will have 4 similar sized portions of dough. Roll one portion at a time into a tube that is 3/4-inch thick.
Use your knife or dough scraper to cut every 3/4-inch across making small gnocchi pieces or pillows. You can leave the shape as is, or roll the pieces gently along the back of a fork creating a lined texture on the surface. Place the final gnocchi onto a lightly floured baking sheet. Repeat with the remaining dough portions until all the gnocchi are made. At this stage you could freeze the tray of gnocchi. Once the pieces are frozen place in a freezer-safe container or bag. You can boil from frozen. Set the sheet of fresh made gnocchi aside or cover with a clean towel.
If making an easy pesto version, combine store-bought pesto with lemon juice and nutritional yeast and set aside at the stove, ready for cooking.
Bring a pot of water to a rolling boil. Once boiling add a generous amount of salt and gently place the gnocchi into the water. They will take about 2 minutes in the water and should start to float. Remove gnocchi with a slotted spoon, draining excess water. Place the gnocchi onto a clean baking sheet or large platter.
Once all the gnocchi is boiled heat a cast iron skillet or non-stick pan over medium heat. When the pan is hot add about 2 tablespoons of olive oil. Place the gnocchi in one even layer. You might need to cook in batches. Pan fry the gnocchi for about 2 to 3 minutes per side only tossing once or twice. Half way through browning the gnocchi you can add minced garlic. Lower the heat slightly to prevent garlic from burning, if necessary. Once the garlic is cooked and the gnocchi are light brown on both sides, add pesto or other sauce of your choice to just heat through and coat the gnocchi gently. Serve immediately and garnish with toasted walnuts, vegan parmesan, and fresh ground black pepper.