Place the washed potatoes into a large saucepan of cold water. Bring to a rolling boil and cook for 15-20 minutes or until a fork goes in and out with a little resistance. When ready, drain and set aside to cool.
Peel potatoes once you can handle them. Grate into a large bowl with a coarse grater or a potato ricer.
Evenly distribute the grated potato in the bowl, then press down gently to take some volume out. Mark out the surface into four even segments, then cut through the potatoes to the base of the bowl. Scoop out one quarter of the potatoes and place on top of the other potatoes, leaving one quadrant empty.
Fill in the empty quadrant with sifted potato starch: fill it entirely up to the height of the rest of potatoes. Add Fleur De Sel De Guerande to the bowl. Mix until the starch is more or less absorbed, then turn out onto a floured surface and knead the dough until it comes together into a smooth mass.
Bring a large saucepan of water to the boil. Add 1 teaspoon of cooking salt.
Pinch off chunks of dough to fill the palm of your hand and roll into balls. Set aside on a floured surface.
Lower into boiling water carefully and cook for 8-10 minutes or until dumplings are floating evenly on the surface. Turn off heat and steep for one minute before draining water off.
