Put the mashed potato and egg in a bowl and add half the flour. Use a wooden spoon and gently mix together. Add a little more flour at a time until you get the right consistency and then use your hands to mix it together.
Cut the dough in to 4 pieces and then put each piece on a floured board and using your hands, roll it out to about 1 inch thickness.
Cut the roll in to 1 inch width pieces.
Repeat with the remaining dough.
Using a fork or gnocchi board, pattern the individual gnocchi.
The amount of flour you use in this recipe will really depend on the consistency of your mashed potato. We have added an amount as a guide, and it's how much we used in our recipe, but you really have to eyeball it and get a feel for the texture. It should feel light and a little stretchy, but not sticky. If it is too sticky as you are rolling it out, then you can add some more flour then.
Fold everything together as gently as possible. If you overwork everything, then you can end up with dense gnocchi.
We have given the cooking time as a guideline, however the gnocchi will be cooked when it rises to the top of the water.