Bring a large pot of salted water to boil. Cook pasta until al dente, then drain and rinse until cold.

Combine basil, olive oil, pine nuts, and garlic in a food processor. Pulse until a paste forms, stopping often to push down the basil. Add the cheese and pulse once more. Taste and adjust salt levels. Set pesto aside in a bowl.

Heat a large pan to medium heat. Pat the chicken dry and season with salt and pepper on both sides. Sear the chicken in olive oil until cooked through (about 3 minutes per side).

Transfer the chicken to a cutting board and cut into strips.

Combine the pasta, sliced chicken, and half of the pesto. Mix well, adding more pesto as needed to achieve desired consistency. Taste and make final adjustments to salt and pepper if required.