In a Dutch oven, melt the butter over medium high heat. Add the onions and garlic and saute until the onions are translucent, about 5 minutes. Add the mushrooms and continue to saute until the mushrooms have softened, about 5 minutes.
Add the flour and stir so that the mushroom mixture is coated in the flour. Add the wine and cook for another minute.
Add the chicken, tomatoes, spinach, chicken broth, milk, and chicken bouillon and stir to combine. Bring the soup to a simmer (not a boil). Cover the Dutch oven and simmer for 20 minutes, stirring occasionally.
Add the parsley, Parmesan cheese and heavy cream. Simmer for another 5 minutes with the lid on the Dutch oven. Add salt and pepper to taste.
Add the pasta to the sauce, and stir to combine.
Serve immediately.
Recipe by The Little Chef at http://littlechefblog.com/pasta-milano/