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

Season sliced chicken breasts generously with salt and pepper. In a large skillet, heat olive oil and butter over medium-high heat. Add chicken and cook for 5-6 minutes on each side until golden brown and cooked through. Remove from heat and slice into strips.

In the same skillet, sprinkle in all-purpose flour and stir continuously for about 1 minute until lightly golden. Slowly whisk in chicken broth, followed by heavy cream, pesto, and lemon juice. Simmer for 3-4 minutes until the sauce is thickened.

Stir in fresh baby spinach into the sauce, cooking for 1-2 minutes until wilted.

Add the drained pasta into the skillet with the sauce, tossing thoroughly. Gradually mix in reserved pasta water for desired consistency.

Plate your pasta, top with sliced chicken, and sprinkle with Parmesan cheese before serving.