Bring the potatoes to the boil in salted water and simmer for about 20 minutes or until completely tender to the point of a knife. Drain, return to the pan on a low heat to steam off any excess moisture. The potatoes should be as dry as possible. Mash the potatoes until completely smooth. Wilt the spinach in a pan – there will be enough moisture in the leaves – until completely soft.
When done, place the leaves in a dry J-cloth or muslin or tea towel and wring to squeeze out as much moisture as possible. When the spinach is absolutely dry, finely chop. Place the potato, spinach, flour and egg yolk in a bowl and season, then mix until completely blended. Dust your hands with a little flour and take a tablespoon of the dough and roll it into a ball. Place on a floured baking sheet. Repeat until you have about 40-50 balls.
Using a fork, press the prongs gently into each ball to make indentations across it. The gnocchi can be frozen at this point. To cook, bring a large pan of water to boiling point, then add the gnocchi in batches and lower the heat. Do not overcrowd the pan. Cook until they rise to the surface – about two minutes, then drain well and cook the next batch. Serve with your favourite pasta sauce.
Freezing and defrosting guidelines
In order to enjoy optimum flavour and quality, frozen items are best used within 3 months of their freezing date. Always defrost and heat thoroughly before eating. For more tips on freezing and defrosting food, read our article Love Your Freezer.