Brown the sausage in a large pot over medium heat with salt and pepper for 6 to 8 minutes, breaking into bite-sized pieces until cooked through. Add 1 tablespoon olive oil if needed.
Add diced onion, minced garlic, and cubed butternut squash with salt and pepper. Cook, stirring often, for 5 to 6 minutes until softened.
Stir in tomato paste and cook for 2 minutes until it darkens and caramelizes.
Add diced fire roasted tomatoes, parmesan rind, and 4 cups chicken stock. Bring to a boil, then reduce to simmer. Cover and simmer for 15 to 20 minutes until squash is fork-tender.
Remove parmesan rind if not dissolved. Stir in heavy cream, kale or spinach, and cheese tortellini. Cook uncovered for 5 minutes until tortellini is tender. Add remaining cup of stock if soup is too thick.
Season with salt and pepper to taste. Serve garnished with grated parmesan cheese and crushed red pepper.
Notes
Fire roasted tomatoes add smoky depth. Substitute with regular diced tomatoes plus ¼ teaspoon smoked paprika.
For vegetarian version, omit sausage and use vegetable stock. Add white beans for protein.
Store leftovers in airtight container in refrigerator for up to 3 days. Tortellini will absorb broth during storage.
Freeze soup base without tortellini and cream for up to 3 months. Add fresh tortellini and cream when reheating.