Charmoula is a spicy Moroccan marinade; it typically contains paprika, cumin, and garlic.
In a large saucepan, combine 2 quarts water, carrots, celery, onion, vinegar, and peppercorns; bring to a boil. Reduce heat; simmer for 20 minutes. Return to a boil and add shrimp. Cook them through, about 3 minutes. Drain shrimp. Remove shells, leaving tail section intact; devein.
Whisk together remaining ingredients, except greens. Add shrimp; toss to coat. Refrigerate for at least 1 hour or overnight. Let stand at room temperature 30 minutes before serving. Serve shrimp on the greens with marinade for dipping.