In a large pot of salted boiling water, cook the fettuccine according to package instructions until al dente. Drain and set aside, reserving about 1/2 cup of pasta water.
In a large skillet, heat the olive oil over medium heat. Add the diced chicken breasts and season with salt and pepper. Cook for about 6-8 minutes until golden brown and cooked through. 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, being careful not to burn it.
Pour in the chicken broth and bring it to a simmer. Allow it to reduce slightly, cooking for about 3-4 minutes.
Stir in the heavy cream, Italian seasoning, and stir until well combined. Bring to a gentle simmer.
Return the chicken to the skillet and add the cooked pasta. Toss everything together, adding reserved pasta water as needed to reach desired creaminess. Fold in the spinach until it wilts.
Remove the skillet from heat and sprinkle in the grated Parmesan cheese, stirring until melted and the sauce thickens slightly. Adjust salt and pepper to taste.
Plate the creamy chicken pasta and garnish with fresh basil leaves and additional Parmesan cheese if desired.
Notes
Adjust the seasoning to your taste and add more cheese if desired.