Pat the chicken breasts dry with paper towels to ensure they sear properly.
Using a sharp knife, make 3-4 shallow slashes across each chicken breast, about ¼ inch deep, to help the herbs penetrate and promote even cooking.
In a small bowl, combine chopped thyme, rosemary, lemon zest, salt, pepper, and 1 tablespoon of olive oil to create a fragrant herb paste.
Rub the herb mixture all over each chicken breast, pressing some into the slashes for deeper flavor infusion.
Preheat a cast iron skillet over medium-high heat until it’s hot and begins to shimmer, releasing a faint aroma.
Add a splash of olive oil to the hot skillet, swirling to coat the bottom evenly.
Place the chicken breasts in the skillet carefully, listening for a sizzle, and sear for 3-4 minutes until golden brown on the first side.
Flip the chicken using tongs, and sear the other side for another 3-4 minutes until golden and fragrant.
Reduce the heat to medium, cover the skillet with a lid, and cook for an additional 8-10 minutes, checking for doneness after 8 minutes.
Insert a meat thermometer into the thickest part of the chicken; once it reads 75°C (165°F), remove the skillet from heat.
Let the chicken rest for 5 minutes on a plate, tented loosely with foil, to allow juices to redistribute.
Slice the chicken breasts and serve immediately, drizzled with pan juices and a squeeze of fresh lemon if desired.
