Take the spinach and blanch them in lightly salted water for a few minutes, then pass them quickly in iced water so that the original color is retained, drain well, squeeze them, and wait for them to cool down.
Once cold, chop them very finely with a knife and place them in a large bowl and add the ricotta cheese, the grated Parmigiano-Reggiano cheese, nutmeg, pepper and salt.
Add the whole egg, flour and mix everything in such a way that the ingredients combine well and become a homogeneous mixture, should it seem too soft or "wet" (because perhaps the ricotta has not been drained well), you just need to add flour little by little until the softness is less and it becomes more homogeneous.
At this point you can shape your gnudi, form small balls (about the size of a walnut), roll them in flour and place them in a well-floured tray and space them apart.
Let them rest in the refrigerator for no more than 20 minutes so that they become more compact and homogeneous.
Make the sauce
In a saucepan, melt the butter.
Chop the aromatic herbs and cook them in the saucepan at low heat.
In another saucepan, toast the pine nuts, and coarsely grind them when toasted.
Cook the gnudi
In a large pot, add water and salt and bring it to a boil.
Take the gnudi from the fridge and start cooking them by adding a few gnudi at a time in the pot with the boiling water. They will be cooked once they rise to the surface, then take them out with a skimmer.
Once all the gnudi are cooked, you can proceed with the seasoning. First, toss the flavored butter, then the pine nuts. If you prefer, you may add some freshly ground pepper and Parmigiano-Reggiano cheese on top, and they are ready to serve!
If you prefer finer spinach, blend the spinach with a blender. The best-known sauce for gnudi is based on butter and sage, but the variation with tomato sauce or meat sauce is very popular.