In a skillet, brown the sausage over medium heat for about 5-7 minutes until it's golden and cooked through. Chop your onion, carrots, and celery, and mince the garlic. Once browned, transfer the sausage along with the chopped veggies into your slow cooker.

To the slow cooker, add the Italian seasoning, beef or chicken bouillon, and a pinch of salt. Pour in the broth while gently stirring to combine the ingredients.

Cover the slow cooker with its lid and set it to cook on low for 7-8 hours or on high for about 4 hours.

Once the soup is ready, use a ladle to skim off any excess fat from the surface. In a separate bowl, whisk together the cornstarch and evaporated milk or half-and-half until smooth. Slowly stir this mixture into the soup.

Gently fold in the cheese tortellini into the soup. Cover the slow cooker and set it to cook on high for an additional 45 minutes.

After the tortellini has cooked, stir in the baby spinach; this will wilt in just about 5-10 minutes.

Assess the thickness of your creamy soup. If desired, add a splash of milk for a creamier texture and season with additional salt and pepper to taste.

Ladle the warm soup into bowls and serve it immediately, perhaps alongside a slice of crusty bread.