Butternut Squash Sausage Tortellini Soup (Cozy One-Pot Dinner)

Ingredients

• 1 tablespoon olive oil, plus more if needed
• 1 lb (450 g) mild Italian sausage, casings removed if using links
• 1 medium yellow onion, diced
• 1 large carrot, diced
• 4 cloves garlic, minced
• 1 tablespoon tomato paste
• 4 cups (560 g) peeled cubed butternut squash
• 1 can (14.5 oz or 410 g) fire-roasted diced tomatoes
• 5 cups (1.2 L) low-sodium chicken broth, plus more as needed
• 1 teaspoon chopped fresh sage or 1/2 teaspoon dried sage
• 1/2 teaspoon kosher salt, plus more to taste
• 1/4 teaspoon black pepper
• 1/4 teaspoon crushed red pepper flakes, optional
• 1/2 cup (120 ml) heavy cream
• 12 oz (340 g) refrigerated cheese tortellini
• 3 cups (75 g) chopped kale or baby spinach
• 1/2 cup (45 g) grated parmesan cheese, plus more for serving