Coat the bottom of a large dutch oven with olive oil and heat over medium heat. Add the onion and saute until softened, about 4 minutes. Add the garlic and saute until fragrant. Add the sliced chicken sausage and cook , stirring occasionally until heated through. Stir in the chicken broth, diced tomatoes, and tomato sauce and bring the mixture to a boil. Add the zucchini and cook for 2 minutes, then add the frozen tortellini and cook for another 5 minutes, or until tortellini is tender and hot clear through. Remove the mixture from heat, and stir in the spinach until wilted. Stir in the cream, Parmesan cheese, basil, and parsley. Season to taste with salt and pepper if needed. Serve warm with additional fresh basil and Parmesan cheese for topping, if desired.