Pat the chicken dry and season with salt, pepper, and Italian seasoning.

Heat olive oil and butter in a skillet, sauté chicken until golden brown, then set aside.

In the same skillet, add more butter and oil, then sauté chopped onion until translucent.

Add minced garlic and cook for 1 minute, then add sun-dried tomatoes, remaining seasoning, and red pepper flakes.

Deglaze with chicken broth and simmer for 2-3 minutes.

Stir in heavy cream and simmer for 5 minutes until thickened.

Add Parmesan cheese and adjust seasoning as needed.

Cook the fettuccine according to package instructions, reserve pasta water, then drain.

Combine the drained pasta with the sauce and cooked chicken, adding reserved pasta water if necessary.

Finish with fresh basil and serve immediately, garnished with extra cheese and red pepper flakes if desired.