Wash and clean potatoes but do not peel them. Fill a large saucepan with cold water, add potatoes, and cook on high heat for 25-30 minutes, or until potatoes are fork-tender.
Drain cooked potatoes, allow to cool for 5-7 minutes, and carefully remove the peel, which should come off easily using your hands.
Pass peeled potatoes through a ricer into a large bowl or mash them using a potato masher, making sure to get rid of large lumps.
Allow mashed potatoes to cool for 10-15 minutes. Then, add salt, flour, and 2-3 tbsp. of beaten egg. Start with the minimum amount of flour (1 cup/120g). Using your hands, work the mixture to a smooth dough (you may need to add some more flour), but do not overwork the dough. Try to work as quickly as possible. The dough should hold together and should not be sticky.
Divide the dough in 4 and roll each piece into a long cylinder (thumb-thickness) onto a lightly floured surface (you don't want the gnocchi dough to stick to the surface as you are rolling into a cylinder).
Slice the dough into 2cm (¾") squares and transfer each piece onto a lightly-floured plate.
You can either leave the gnocchi smooth or your can create ridges (that are meant to hold the sauce).For ridged gnocchi, roll each piece onto a lightly-floured gnocchi board or ruler. If you don't have an gnocchi board, you can roll each piece over the back of a fork.
Before cooking, allow gnocchi to rest, uncovered, on a lightly floured surface at room temperature for 15-20 minutes. This will dry them out slightly and prevent them from sticking together whilst cooking. In the meantime, you can prepare the sauce.