In a large pot or Dutch Oven over medium heat, add the olive oil and chopped onion.

Use your fingers to squeeze ¾-inch balls of sausage meat out from the casings. Let them fall directly into the pan of onions. Stir occasionally as you make all the sausage balls. Discard casings. Stir until well browned.

Add the broth, water and salt to the large pot with the sausage. Cover and increase heat to high.

When it reaches a simmer add the orzo. Let it come to a boil. Reduce heat to a heavy simmer. Stir occasionally until the pasta is al dente, about 6 minutes. Meanwhile, grate the parmesan cheese if not pre-grated.

When the pasta is cooked (the sausage will be cooked by now as well), taste and add extra salt if desired. Put a handful of spinach into each of 4 soup bowls. Ladle hot soup on top of spinach. Garnish with grated Parmesan.