Trim any fat from the chicken and cut into 1-inch cubes; season with 2 teaspoons Italian seasoning, about 1/2 teaspoon kosher salt, and a pinch of black pepper.
Heat 1 tablespoon extra virgin olive oil in a large deep sauté pan over medium-high heat. Add the chicken and cook without moving for about 2 minutes to brown, then stir and cook until browned on all sides, about 2–3 more minutes.
Add the diced shallot to the pan and sauté, stirring often, until the shallot softens and the chicken is cooked through and browned, about 2–3 minutes.
Reduce heat to medium, add the minced garlic, and sauté for 30–60 seconds until fragrant but not burned.
Pour in 2 cups low-sodium chicken broth and scrape the pan to deglaze, loosening any browned bits. Stir in the remaining Italian seasoning and the crushed red pepper flakes (if using). Bring to a light boil.
Add 8 oz dry pasta, pushing it down so it is submerged in the broth. Cover, reduce heat to medium-low, and cook for 10–13 minutes until the pasta is almost al dente, stirring every 2–3 minutes and briefly replacing the lid each time.
Remove the lid and stir in 1/2 cup finely grated Parmesan cheese and 1/2 cup heavy cream. Stir until the Parmesan melts and the sauce thickens slightly. Taste and adjust salt and pepper as needed.
Serve immediately garnished with freshly minced parsley, if desired.
