Cook the Pasta: Bring a large pot of salted water to a boil. Add pasta and cook until al dente, about 8-10 minutes. Reserve 1 cup of pasta water, drain and set aside.

Sauté the Chicken: Heat 2 tbsp butter in a skillet. Add chicken and cook for 6-8 minutes until golden brown. Remove chicken and set aside.

Create the Sauce: Melt remaining butter, add garlic and onion, sauté for 3-4 minutes until onion is translucent.

Add Cream and Broth: Pour in heavy cream and broth, adding Italian seasoning and red pepper flakes. Let simmer for 5 minutes, adjusting thickness with reserved pasta water.

Combine Ingredients: Return chicken and pasta to skillet, toss gently and cook for 2 minutes to combine flavors.

Serve and Garnish: Remove from heat, serve immediately with grated Parmesan and fresh parsley.