In the meantime, put the spinach in a large saucepan, cover with cold water, salt slightly and bring to the boil. Let it simmer until tender. Drain the spinach and let it cool, then squeeze it as hard as possible to remove all the liquid retained.

Finely chop the spinach and place it in a large bowl. Peel the potatoes and, still hot, pass them to the potato masher directly in the bowl with the spinach.

Transfer the dough to the floured pastry board and add the flour a little at a time, kneading with your hands until you get a fairly consistent dough. Depending on the amount of moisture in the potatoes and spinach, it may be necessary to add more or less flour, so use only enough to tie the ingredients together.

Take a piece and roll it in a sausage about 1.5 cm thick. Cut into 2 cm long pieces and place them on a floured cloth.

Melt the butter in a saucepan over low heat together with the sage, swirling the pan over the heat, until the butter completely melts. Keep the sauce warm.

Cut the speck into strips and sauté them in a very hot non-stick pan, without adding fat, for about a minute.

In the meantime, bring a large pan with salted water to a boil. Lower one serving of dumplings at a time into the water and cook until the dumplings float on the surface. Drain them with a slotted spoon and place them on the plate. Sprinkle the gnocchi with parmesan and melted butter.

Garnish with fresh sage, if desired.