Thoroughly pat the chicken thighs dry with paper towels on both sides. Moisture is the enemy of crispy skin! Season generously all over with sea salt, black pepper, garlic powder, and paprika.

Heat olive oil in a large 12-inch cast-iron skillet over medium-high heat until shimmering. Place the chicken thighs skin-side DOWN in the skillet. Do not overcrowd (work in batches if needed).

Sear undisturbed for 12 to 14 minutes over medium heat without moving them. As the chicken fat renders, the skin will turn deep amber, blistered, and shatteringly crisp.

Flip thighs skin-side UP and cook for another 8 to 10 minutes until the internal temperature reaches 165°F (74°C) on a digital meat thermometer. Transfer chicken to a warm plate (do not cover tightly or skin will soften).

Drain excess chicken fat from the skillet, leaving about 1 tablespoon of rich pan drippings. Return skillet to medium heat.

Add minced garlic and lemon slices. Sauté for 1 minute until garlic is fragrant and lemon rounds are lightly caramelized.

Pour in the chicken broth and fresh lemon juice, scraping up all the golden caramelized browned bits (fond) stuck to the bottom of the skillet with a wooden spoon. Simmer for 2 to 3 minutes until liquid reduces by half.

Reduce heat to low and whisk in the cold butter cubes and fresh herb sprigs (rosemary and thyme). Whisk continuously until the butter melts into a glossy, velvety emulsion.

Nestle the chicken thighs back into the skillet around the caramelized lemon rounds. Spoon the luxurious garlic herb pan sauce over the bottom of the thighs, keeping the crispy golden skin dry on top!

Garnish with freshly chopped parsley, a sprinkle of flaky sea salt, and serve immediately straight from the sizzling skillet.