I live in an area rich with Italian heritage. This recipe is from a very old, Italian Catholic church cookbook submitted by one of the best cooks in the area. I make these quite often. It's beautiful served with an Alfredo sauce or browned butter sauce with sage and additional freshly shaved Asiago or Parmesan. Some also serve with pasta sauce and meatballs or Italian sausage.
Cook frozen spinach in microwave and cool completely. When cool, squeeze out any liquid until dry.
Add all ingredients into food processor EXCEPT flour and process for 30-60 seconds until spinach is broken into tiny pieces, but specks of dark green remain. (You don't want it a uniform color.)
Place spinach mixture into a large bowl and add 2 cups of flour. Mix well. Using your hands, add flour 1/4 cup at a time until a stiff dough is achieved that you can roll into ropes. It will be a work out for your arms! =) (I roll a test piece in my hands to see if it's ready.) The amount of flour depends on how dry you get your spinach. I usually use 2 1/2- 2 3/4 cups total. You'll be flouring your board also. Too dry and it won't form a nice rope. Too wet and it's too sticky.
Place dough ball on a dinner plate. Lightly flour your counter top or board. Cut dough ball every 3/4" or so and then form these chunks of dough into ropes about the same size around as your thumb. Cut ropes into 1" chunks. (If you see a string from the spinach, just pat it down.) Place on large parchment lined cookie sheet with a sprinkling of flour. Continue until all dough is cut into 1" pieces. If you have time and patience, you can roll each gnocchi off of the tines of a fork forming ridges, but I never do.
Drop into salted slow boiling water and give a stir so they don't stick to the bottom. Boil gently until they rise to the top. (3-5 minutes) Drain. Serve with freshly shaved Parmesan or Asiago cheese and your favorite pasta sauce, Alfredo sauce, browned butter/sage sauce, whatever you like.