Bring a large pot of salted water to a boil. Add the fettuccine and cook until al dente, about 8-10 minutes. Save 1/2 cup of the pasta water, then drain and set aside.

Season chicken cutlets with garlic powder, salt, and pepper. Heat a skillet over medium-high heat with olive oil and butter. Cook chicken for 5-6 minutes per side until golden and reaches 165°F. Remove and let rest.

In the same skillet, add all-purpose flour and cook for about 1 minute. Gradually pour in chicken broth, scraping the bottom of the pan. Stir until thickened.

Lower heat and stir in heavy cream and pesto. Squeeze in lemon juice and add sun-dried tomatoes. Simmer for 3-4 minutes.

Add spinach, stirring for about 2 minutes until wilted. The color will blend with the creamy sauce.

Mix in drained fettuccine, tossing to coat. If thick, add reserved pasta water to adjust consistency.

Slice chicken into pieces and arrange on top of pasta. Top with Parmesan cheese if desired and serve warm.