01 - In a medium bowl, combine parsley, cilantro, garlic, shallot, red wine vinegar, olive oil, oregano, red pepper flakes, salt, black pepper, and lemon juice. Stir well to form a vibrant, herby chimichurri sauce.
02 - Reserve 1/3 cup of the chimichurri for finishing. Pour the remaining sauce over the peeled and deveined shrimp in a large bowl or zip-top bag, tossing to coat evenly. Allow to marinate at room temperature for 15 minutes.
03 - Preheat an outdoor grill or grill pan to medium-high heat, ensuring the grates are clean and lightly oiled to prevent sticking.
04 - Thread the marinated shrimp onto skewers, spacing them evenly. If using wooden skewers, soak them in water for at least 30 minutes prior to prevent burning.
05 - Place skewers on the hot grill and cook for 2 to 3 minutes per side, turning once, until the shrimp are opaque throughout and lightly charred on the edges.
06 - Transfer the grilled shrimp to a serving platter, drizzle generously with the reserved chimichurri sauce, and serve immediately while hot.