Bring a large pot of salted water to a rolling boil. Add pasta and cook according to package instructions until al dente, about 8-10 minutes. Reserve ½ cup of pasta water, then drain and set aside.

Season sliced chicken breasts with garlic powder, salt, and pepper. Heat olive oil and butter in skillet over medium heat. Cook chicken for 5-6 minutes on each side until golden brown and cooked through. Transfer to a plate to rest, then slice.

In the same skillet, sprinkle in all-purpose flour, stirring continuously for about 1 minute to create a roux. Ensure it turns slightly golden and releases a nutty aroma.

Gradually pour in chicken broth, stirring to deglaze the pan. Add heavy cream, pesto, lemon juice, and sun-dried tomatoes. Let simmer for 3-5 minutes until slightly thickened.

Stir in fresh spinach and cook for 2-3 minutes until wilted. Keep the heat low to maintain warmth.

Add drained pasta to the skillet, tossing with the sauce to coat. If sauce is too thick, add reserved pasta water gradually until desired consistency is reached.

Serve pasta with sliced chicken on top and sprinkle with grated Parmesan if desired. Enjoy!