Heat a heavy bottomed saucepan over medium high heat. Add the olive oil and sausage. Cook stirring for about 2 minutes or until cooked through. Remove the sausage with a slotted spoon. Reserve.
In the same pan, add the onions and cook over medium high heat. Cook until light golden at edges. Add the garlic and cook 30 seconds. Add the couscous and the broth. Cover and bring to a full boil. Stir occasionally. After 5 minutes, stir in the butternut squash. Continue cooking, stirring occasionally. Remove the lid and continue cooking until most of the liquid has been absorbed. Take care not to mash up the squash cubes.
Stir in the spinach and reserved sausage meat, and season to taste with salt, black pepper, and Parmesan cheese.