Pat chicken thighs dry with paper towels.
Season chicken with salt and pepper.
Rub olive oil on both sides of chicken.
In a bowl, add parsley, garlic, and oregano.
Pour in olive oil and red wine vinegar.
Add crushed red pepper, salt, and pepper.
Mix the chimichurri until fully combined.
Reserve half sauce for later serving.
Coat chicken with half of the sauce.
Cover and marinate for 30 minutes.
Preheat oven to 400°F or grill to medium-high.
Bake for 35–40 minutes or grill until done.
Turn chicken halfway through cooking.
Remove and rest chicken for 5 minutes.
Drizzle with reserved chimichurri before serving.