In a medium bowl, whisk together the olive oil, lemon juice, oregano, dried basil, garlic powder, and a pinch of salt and pepper. Add the chicken breasts to the bowl, ensuring they are thoroughly coated with the marinade. Cover with plastic wrap and refrigerate for at least 30 minutes to enhance the flavor.
In a food processor, combine the fresh basil leaves, toasted pine nuts, grated Parmesan cheese, minced garlic, and 1/2 cup of extra-virgin olive oil. Pulse until the mixture is smooth and creamy. Taste and season with salt and pepper as needed. Set aside while you complete the other steps.
Bring a large pot of salted water to a vigorous boil. Add the pasta and cook according to the package instructions until it reaches an al dente texture. Just before draining, reserve 1/2 cup of the pasta cooking water. Drain the pasta and set it aside.
Heat a grill or grill pan over medium-high heat. Once hot, place the marinated chicken on the grill. Cook for about 6-7 minutes on each side, or until the chicken is fully cooked through and has an internal temperature of 165°F (75°C). Once done, remove the chicken from the grill and let it rest for a few minutes before slicing it into strips.
In a large mixing bowl, combine the drained pasta and the prepared pesto sauce. Toss gently until the pasta is evenly coated. If the pesto seems too thick, gradually add the reserved pasta water until the sauce is at your desired consistency.
Arrange the sliced grilled chicken over the pesto-coated pasta. Garnish with halved cherry tomatoes for a fresh touch and a burst of color on the plate.
Notes
For an elevated presentation, serve the pasta in deep bowls, layering the chicken on top, and sprinkle with additional Parmesan and a few whole basil leaves for a vibrant finish.