Trim excess fat from the chicken thighs and pat them dry with paper towels. If any pieces are very thick, pound gently to an even thickness (about 3/4 inch) so they cook evenly.

Make the marinade

In a medium bowl, whisk together olive oil, soy sauce, lemon juice, honey, minced garlic, grated ginger, smoked paprika, black pepper, kosher salt, and red pepper flakes until combined.

Marinate the chicken

Place the chicken in a resealable plastic bag or a shallow dish. Pour the marinade over the chicken, ensuring all pieces are well coated. Add chopped parsley and press out excess air from the bag, or cover the dish with plastic wrap. Refrigerate for at least 30 minutes and up to 8 hours. For best flavor, marinate 2–4 hours. If short on time, even 15–30 minutes will add flavor.

Cook / Finish

Bring to room temperature

Remove the chicken from the refrigerator 15–20 minutes before cooking to take the chill off; keep it in the marinade.

Heat pan

Heat a large skillet or cast-iron pan over medium-high heat. Add neutral oil and heat until shimmering but not smoking.

Sear the chicken

Remove chicken from the marinade, letting excess drip back into the bowl. Reserve remaining marinade. Place chicken thighs in the hot pan in a single layer without crowding (work in batches if needed). Cook undisturbed for 4–5 minutes until a deep golden crust forms.

Flip and baste

Flip the thighs and reduce heat to medium. Add butter (if using) and 1–2 tablespoons of the reserved marinade to the pan. Cook for another 4–6 minutes, spooning the melted butter and marinade over the chicken to glaze, until the internal temperature reaches 165°F (74°C).

Rest and serve

Transfer chicken to a cutting board and let rest 5 minutes. Slice against the grain if desired, sprinkle with additional chopped parsley, and serve with lemon wedges for squeezing over the top.