Pat the chicken breasts dry with paper towels, then lightly score the thick side with a sharp knife to promote even cooking.
In a small bowl, whisk together olive oil, fresh lemon juice, salt, and pepper. Brush this mixture generously over both sides of each chicken breast.
Preheat your grill or cast-iron pan over medium-high heat until it shimmers and is hot to the touch, about 200-230°C (390-450°F).
Place the chicken breasts on the grill, presentation side down, and cook for 5-6 minutes until deep grill marks and a golden crust form.
Flip the chicken breasts carefully using tongs, then cook for another 5-6 minutes, ensuring even searing and listening for a gentle sizzle.
Insert a meat thermometer into the thickest part of each breast; once it reads 74°C (165°F), remove the chicken from the grill.
Transfer the grilled chicken to a plate, loosely cover with foil, and let rest for 5 minutes to allow juices to redistribute.
Uncover and check that the juices run clear and the meat feels tender but firm. Slice against the grain for serving.
Serve the juicy, smoky chicken breasts with your favorite sides, enjoying the crispy crust and tender interior.
