Method:
Drain the ricotta well. Cook the cleaned spinach in boiling salted water for 2/3 minutes. Drain them and immediately pass them under cold water. Squeeze and chop them with a knife and pass them in a pan with a little oil and garlic to flavor them.
After two minutes, squeeze them again and put them in a bowl. Add the ricotta and mix everything. Add the yolk and half of the grated Parmesan (the rest will be used to season them at the end).
Mix, add salt and flavor with a pinch of nutmeg. Add one or two tablespoons of flour to dry the dough a little.
Put the remaining flour on the plate. Shape into balls with the help of two spoons or with your hands and roll them in flour.
Boil the water and salt in a large pot. When it boils, throw away a part of gnudi (half of those prepared).
From the moment they come to the surface let them cook two or three minutes. Then drain them with a slotted spoon and put them in a pan with butter and sage. This operation is done twice to ensure that when they come to the surface there are not too many and they do not deform as they are very delicate.
Cook the other half of the gnudi in the same way.
Sauté them in a pan with butter and sage, mixing them gently otherwise they break!
Serve hot sprinkled with a nice handful of Parmesan, hot and racy, good appetite!