Pierce the skins of the sweet potatoes and microwave until soft. Scoop the insides out and place in a bowl. Mash with the back of a spoon to make sure there are no lumps and leave to cool.
Add the egg and salt to the mashed sweet potato and mix.
Sieve about half the flour into the bowl of sweet potato and mix using a fork. Add the rest of the flour a little at a time until the mixture forms a ball of dough which is no longer sticky.
Take part of the dough and roll out on a floured board to form a sausage about 12 mm (about half and inch) in diameter. Cut into lengths of about 20 mm (about three quarters of an inch). Roll each piece of dough over an implement to form grooves in the dumpling such as the back of a fork or the wires of an egg slicer. Place on a floured board until ready to cook.
To cook the gnocchi
To boil - bring a large pan of water to the boil. Add the gnocchi, bring back to the boil and then simmer until cooked. The gnocchi will be cooked when they float to the top of the water. Drain and then serve. To fry - boil as above, dry and then fry in a little extra virgin olive oil or butter until golden. Toss part way through cooking. To cook in the oven - add the uncooked gnocchi to your baked sheet pan dinner and the gnocchi will cook along with the rest of your meal.
Notes
To serve
Serve as a first course in a light sauce such as butter and sage or pesto.
Serve as part of a main dish as a substitute for pasta shapes or as part of a baked sheet pan dinner.
Prepare smaller gnocchi for adding to soups or stews.
To store
Store in the fridge for 1 to 2 days.
Sweet potato gnocchi are perfect for freezing. Lay on a tray, freeze and then transfer to an airtight container in the freezer where they will keep for up to one month. Your homemade gnocchi can be cooked from frozen.