In a medium bowl, combine the parsley, cilantro, olive oil, red wine vinegar, garlic, red pepper flakes, salt, black pepper, and lemon juice. Mix well to create the chimichurri sauce.
In a large skillet over medium-high heat, add the shrimp. Cook for about 2-3 minutes on each side, or until they turn pink and opaque.
Once the shrimp are cooked, remove them from the heat and pour the chimichurri sauce over the shrimp. Toss to coat evenly.
Serve immediately, garnished with additional parsley or lemon wedges if desired.