Heat the olive oil in a large stockpot over medium heat. Add Italian sausage and onion. Cook until browned. Drain any grease.
Add the garlic, Italian seasoning, salt and pepper to sausage. Stir and cook for a couple of minutes. Sprinkle flour all over the mixture. Continue to stir and cook for another minute.
Slowly stir in chicken broth, tomato sauce, diced tomatoes, and sugar. Bring to a boil then turn heat to low. Allow soup to simmer, stirring occasionally, until reduced and slightly thickened, about 10 minutes.
Stir in tortellini; cover with lid. Cook until tortellini is tender, about 5 to 8 minutes. Remove the lid and stir in chopped Kale and the heavy whipping cream. Stir until the Kale is wilted and the soup is heated through. Serve warm with shaved Parmesan cheese. Enjoy!