Bring a large pot of salted water to a boil. Add the fettuccine pasta and cook according to package instructions until al dente, usually about 8-10 minutes. Stir occasionally to prevent sticking.

Once cooked, reserve 1 cup of pasta water, then drain the pasta in a colander and set aside.

While the pasta is cooking, season the chicken breasts with salt and black pepper on both sides.

In a large skillet, heat the olive oil over medium-high heat. Once hot, add the chicken breasts and cook for about 6-7 minutes on each side, or until golden brown and cooked through. The internal temperature should reach 165°F (74°C).

Remove the chicken from the skillet and let it rest for a few minutes before slicing it into strips.

In the same skillet used for the chicken, reduce the heat to medium and add the minced garlic. Sauté for about 30 seconds until fragrant, being careful not to burn it.

Add the chicken broth and bring to a simmer, scraping any browned bits from the bottom of the skillet for added flavor.

Stir in the heavy cream, sun-dried tomatoes, dried basil, oregano, and red pepper flakes (if using). Allow the sauce to simmer for about 5 minutes, stirring occasionally until it thickens slightly.

Add the fresh spinach and cook for another 2-3 minutes until wilted. Stir in the grated parmesan cheese until melted and combined.

Add the cooked fettuccine to the sauce, tossing to coat the pasta evenly. If the sauce is too thick, add reserved pasta water a little at a time until desired consistency is reached.

Finally, add the sliced chicken on top and gently mix to combine. Taste and adjust seasoning if necessary.

Serve immediately, garnished with additional parmesan cheese and fresh basil if desired.