In a large pot with just enough water to cover them. Boil potatoes until tender, remove the pot and let it cool remove the skin. Then pass through a potato ricer. Keep aside.
In a medium pot, boil water. Place the spinach into boil for 3 minutes. Hold it over the sink and squeeze out as much water as possible. place the spinach in a food processor and blend until pureed. If needed, add a splash of water into help the spinach blend.
Mound riced potatoes on the middle a wooden board or a Clean, dry counter top.Add the spinach puree, flour, parmesan cheese powder, black pepper powder, salt, nutmeg powder and mix well knead into a soft dough.The dough will be sticky. If it's very sticky add more flour about one tbsp.
Roll the dough into a ball and cut it even pieces. Roll each piece into a long rope that's about 1/2 an inch thick. Cut the gnocchi into 1 inch pieces. Press again the back of a fork for the characteristic pattern.
Place each gnocchi on a floured board.
Now a large pot of lightly salted water to a boil over high heat. Add the gnocchi and cook until they float to the surface 2to3 minutes and drain the water.
Melt the butter in a skillet over medium heat. Add the boiled gnocchi.cook 2-3 minutes and toss gently.
Transfer to a serving plate and sprinkle parmesan cheese and serve.
