Heat the olive oil in a large pot over medium-high heat. When the oil is hot, but not smoking, add the sausage.
Cook the Italian sausage for approximately 3-4 minutes until it is browned. Stir the sausage frequently while breaking up any large pieces with a wooden spoon or spatula.
Lower the heat to medium and add the onions and carrots to the pot.
Cook the vegetables with the sausage for 2-3 minutes until the onions are translucent, stirring frequently.
Add the garlic and cook for 1 minute, stir frequently.
Add the flour to the pot and cook for 1 minute, stirring constantly.
Add the chicken broth to the pot while gently scraping any bits off the bottom. Raise the heat to high and bring the broth to a boil.
Once the soup comes to a boil, lower the heat to medium-low and cover the pot. Keep the soup at a simmer and cook for 15-20 minutes, stirring occasionally.
Raise the heat to medium-high and bring to soup to a full boil.
Add the potatoes and the cannellini beans.
Lower the heat to medium, cover and continue cooking the soup for 15-20 minutes, or until the potatoes are tender.
Remove the pot from the heat. Add the half and half to the soup and stir until incorporated. Now, place the pot back over medium-low to low heat but do not allow the soup to come to a boil.
Add the spinach to the Tuscan soup. Heat it gently until the spinach wilts. This will only take a minute or two, stir occasionally.
Taste the Tuscan Soup and add salt, if needed. As a reference, we didn’t add extra salt to our soup.