Line a large plate with 3 sheets of paper towel.
Add the Italian sausage in a large, heavy-bottomed pot over medium heat and use a wooden spoon to break the meat into chunks.
Cook until browned and thoroughly cooked through about 5-6 minutes.
Transfer the sausage to the paper towel-lined plate to drain.
Increase the heat to medium-high, add the onion, and cook until translucent and starting to brown on the edges, about 4 minutes.
Add the garlic and cook until fragrant, about 30 seconds.
Add the chicken broth, tomatoes, beans, tortellini, Italian seasoning, salt, and pepper, and increase the heat to high.
Bring the mixture to a low boil, and then reduce the heat to low and cook for 8 minutes.
Stir in the sausage, cream, Parmesan, and basil and cook for 2 additional minutes.
Ladle soup into bowls and serve with garnishes of shredded Parmesan cheese and chopped basil.