Pat the chicken breasts dry with paper towels to remove excess moisture, which helps achieve a crisp sear.
Heat the cast iron skillet over medium-high heat until it’s just starting to shimmer and feels hot to the touch.
Add the olive oil to the hot skillet, swirling to coat the surface evenly. Wait until the oil shimmers and just begins to smoke slightly.
Carefully place the chicken breasts in the pan, smooth side down, and press lightly to ensure good contact. Sear without moving for about 4-5 minutes until the crust is deep golden brown.
Flip the chicken breasts using tongs and cook for another 4-5 minutes, or until the internal temperature reaches 65°C (149°F). Use the thermometer to check for perfect doneness.
Once cooked, transfer the chicken to a plate and tent loosely with foil. Let it rest for 5 minutes to retain juices.
While the chicken rests, pour the white wine or broth into the hot skillet to deglaze, scraping up all the browned bits with a wooden spoon until the liquid is bubbling and fragrant.
Add a squeeze of fresh lemon juice and some lemon zest to the sauce, stirring to combine and reduce slightly until glossy, about 2 minutes.
Slice the rested chicken against the grain into thick strips, then arrange on a serving plate. Spoon the pan sauce over the top.
Finish with a final squeeze of lemon and sprinkle with fresh herbs if using. Serve immediately for maximum crispness and flavor.
