Cook pasta for 1 minute less than the recommended cook time.

Drain pasta and set aside.

Heat 1 tablespoons olive oil in a large pot on medium heat. Add chicken and season with pepper. Cook chicken until browned and cooked through. Set aside.

Add 1/2 tablespoon olive oil and onion to pot, saute for 5 minutes until onions are translucent.

Add garlic and red chili flakes into the pot and stir.

Add crushed tomatoes, stirring for one minute.

Add half and half and stir until combined.

Add spinach and stir until the spinach is wilted.

Add chicken, pasta, and Parmesan, stirring until pasta is evenly coated.