Add olive oil to a pan over medium heat. Add in frozen spinach and frozen butternut squash and cook until thawed. If using fresh, start by cooking the butternut squash, then add in the spinach once it is soft.
Add in pears once the butternut squash and spinach are no longer frozen. Cook until they begin to soften, another 5 minutes or so.
Add in cooked sausage and cook until warmed. Top with feta and parsley, if desired.