Start by bringing a large pot of salted water to a rolling boil over high heat. Once boiling, add your chosen pasta and cook until al dente, typically around 8-10 minutes. Reserve about ½ cup of the starchy pasta water, then drain the pasta in a colander and set aside.

While the pasta cooks, season the sliced chicken breasts with garlic powder, salt, and pepper. In a large skillet over medium heat, add olive oil and butter. Cook the chicken for 5-6 minutes on each side until golden brown and the internal temperature reaches 165°F. Remove from skillet, let rest, and slice into bite-sized pieces.

In the same skillet, reduce heat to low and sprinkle in all-purpose flour. Stir constantly for about one minute to create a roux.

Gradually pour in the chicken broth while stirring continuously. Scrape up any browned bits from the bottom of the skillet to enhance flavor. Continue stirring until smooth and begins to simmer, about 2-3 minutes.

Mix in heavy cream, pesto, lemon juice, and sun-dried tomatoes into the skillet. Stir well and let it cook for about 5 minutes, or until it thickens slightly.

Once the sauce has thickened, stir in fresh baby spinach and let it wilt for about 2 minutes.

Add the drained pasta to the skillet, tossing everything together until the pasta is well coated. Use reserved pasta water if the sauce seems too thick.

Gently incorporate the sliced chicken into the pasta mixture. Serve immediately, optionally sprinkling Parmesan cheese on top.