To a large pot or Dutch oven over medium heat, add oil, Italian sausage, onion, garlic, salt, black pepper, and red pepper flakes.
Cook, stirring occasionally and breaking up the meat as you go, for about 8-10 minutes, or until the meat is no longer pink. Discard excess grease if necessary.
Add the pasta, chicken broth, and heavy cream. Bring to a simmer and reduce heat to low. Cook, stirring often, scraping up the browned bits until the orzo is tender, about 8-10 minutes.
Add the parmesan and spinach. Stir until the parmesan is melted and the spinach has wilted, about 2-3 minutes.
Garnish with parsley. Serve.
