In a large saucepan heat the oil over medium-high heat, add the onion, mushrooms, and sausage cook until slightly browned. Add the orzo and garlic and cook 1 minute more.
Add the Marsala and scrape up any bits stuck to the bottom of the pan.
Slowly pour in the chicken broth and bring to a boil, reduce heat to medium-low. Simmer uncovered, stirring occasionally, about 7 to 8 minutes or until the liquid is absorbed.
Take off the heat and stir in the frozen spinach and Parmesan cheese. Add salt and pepper to taste.
