In a large skillet, over medium heat, add olive oil and Italian sausage; cook for 4 to 5 minutes until completely browned.
Add onion and garlic; cook for an additional 4 to 5 minutes.
Drain excess grease and add to the crock pot.
Add chicken broth, diced tomatoes, tomato paste, black pepper, salt, thyme, Italian seasoning and corn starch.
Mix all ingredients together until well combined.
Cook on low for 8 hours or on high for 4 hours.
Thirty minutes before the cooking time is done, add in the tortellini, Parmesan cheese, spinach and heavy cream; mix until well combined.
Serve while hot and garnish with fresh grated Parmesan cheese.
