Boil the potatoes with their skin until fork tender in salted water.

Drain the water from the potatoes and let them cool for some minutes. Peel the potatoes.

Mash the potatoes or use a potato ricer. Add egg yolk and flour on top of the mashed potatoes and sprinkle some salt.

Start working all ingredients together. Start with a fork and continue with your hands until you have formed a smooth dough. Don't knead too much or the Gnocchi will be gummy.

Divide the dough into 8 pieces and roll each piece into ropes to a thickness of your thumb. Cut each rope into 1-inch long pieces. Press a fork gently against the gnocchi to create ridges.

Boil in salted water until the gnocchi starts to float up to the surface. Drain and serve with melts butter, tomato sauce or other preferred sauce.

Fry boiled Gnocchi on medium heat in butter. Add the sage when they start to get a nice golden color and fry for an additional 2 minutes.

Add the Ruccola, salt and pepper and stir before pouring it all up on dinner plates. Sprinkle some grated Parmesan cheese on top.