Finely chop parsley and garlic. In a bowl, combine with olive oil, red wine vinegar, oregano, salt, pepper, and red pepper flakes. Mix well to create chimichurri sauce.

Pat chicken thighs dry and season with remaining salt. Ensure even coverage on both sides.

Preheat grill pan or skillet over medium-high heat for 3-4 minutes. Add a splash of olive oil if using a skillet.

Cook seasoned chicken thighs for 5-7 minutes on each side until golden brown and fully cooked (internal temperature of 165°F).

Let chicken rest for 2-3 minutes covered loosely with foil.

Spoon chimichurri sauce generously over each piece of hot chicken and serve.