Pat the chicken thighs dry with paper towels. Season both sides with kosher salt and black pepper.
Heat the olive oil in a large oven-safe skillet over medium-high heat until shimmering.
Add the chicken thighs skin-side down to the skillet. Cook without moving for 6 to 8 minutes until the skin is golden brown and crispy.
Flip the chicken thighs and cook for an additional 4 minutes on the other side.
Remove the chicken from the skillet and set aside on a plate.
Reduce the heat to medium. Add the minced garlic to the skillet and sauté for 30 seconds until fragrant, stirring constantly to prevent burning.
Pour in the chicken broth, lemon juice, and add the lemon zest and dried oregano. Stir to combine and scrape up any browned bits from the bottom of the skillet.
Return the chicken thighs to the skillet, skin-side up. Spoon some sauce over the chicken.
Transfer the skillet to a preheated oven at 375°F (190°C) and roast for 20 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
Remove the skillet from the oven. Place the butter in the skillet and spoon the sauce over the chicken while the butter melts to enrich the sauce.
Sprinkle the chopped fresh parsley over the chicken before serving.