Preheat a grill pan or skillet over medium-high heat. Add olive oil to the pan to prevent sticking.

Season the chicken breasts with salt and black pepper on both sides. This enhances the flavor of the chicken.

Place the chicken breasts in the hot pan and cook for 6-7 minutes on each side, or until the internal temperature reaches 165°F (75°C).

Remove the chicken from the pan and let it rest for 5 minutes before slicing. This allows the juices to redistribute, keeping the chicken moist.

In a food processor, combine the basil leaves, parmesan cheese, toasted pine nuts, minced garlic, and salt.

Pulse the mixture until finely chopped. This helps to release the oils from the basil and the flavors to meld.

With the processor running, slowly drizzle in the olive oil until the pesto reaches your desired consistency. Taste and adjust seasoning if necessary.

In a large mixing bowl, combine the mixed greens, cherry tomatoes, cucumber, red onion, and feta cheese.

Slice the rested chicken breasts into strips and add them to the salad bowl.

Drizzle the prepared pesto over the salad and toss gently to combine, ensuring all ingredients are coated with the pesto.

Serve immediately for the best flavor and freshness.