In a large Dutch oven, cook the sausage on medium heat until browned. Transfer to a paper towel-lined plate.
Add the onion and carrots to the Dutch oven and cook for 5 minutes or until they're soft. Add the garlic and cook 1 to 2 minutes or until its fragrant. Stir occasionally to keep it from burning.
Whisk in the flour and cook it for one minute, stirring continuously.
Gradually add the chicken broth. Whisk to combine. Cook until the mixture almost comes to a boil. Reduce the heat to simmer and allow it to cook for 5 to 6 minutes.
Add the sausage, pasta, salt, pepper, Italian seasoning, spinach, and heavy cream. Stir. Simmer 5 to 6 minutes.