Bring 3 cups of water to a boil. Add the garlic, carrot, celery, lemon, onion, and pepper to the water and cook for 10 minutes. Add shrimp and poach for 1-2 minutes. Strain the liquid and reserve. Pick shrimp out and discard all solids.
While the water is coming to a boil, put red onions and salt in a bowl and let them rest, about 5 minutes. Add lime juice, ketchup, tomatoes, hot sauce, EVOO, cilantro, shrimp and reserved poaching liquid to the onions and combine.
Chill for 20 minutes. Top with popcorn and serve.