Cook the fettuccine or spaghetti according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the chicken pieces and season with salt and pepper. Cook until the chicken is golden brown and cooked through, about 5-7 minutes. Remove the chicken from the skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 1 minute until fragrant. Be careful not to burn it.
Pour in the heavy cream and bring to a simmer. Stir in the Parmesan cheese and Italian seasoning, mixing until the cheese is melted and the sauce is smooth.
Add the cooked chicken back into the skillet along with the fresh spinach. Stir until the spinach wilts and everything is well combined.
Toss the cooked pasta into the skillet, mixing until the pasta is coated with the creamy sauce. Adjust seasoning with salt and pepper if needed.
Serve immediately, garnished with chopped parsley.