Chop the shrimp into bite-sized pieces and place them in a 9x13 inch pan. Pour your lime juice over the shrimp and cover the pan with saran wrap. Let it sit out at room temperature for 1 hour, then place the pan in the fridge to continue "cooking" for 1-2 more hours.
While the shrimp is "cooking", cut your tomatoes, cucumber, onion, jalapeno and cilantro. Keep them stored in the fridge until the shrimp is done.
Once the shrimp is done "cooking", stir in the rest of your ingredients.
Serve with avocado (if desired) and your favorite tortilla chips or spooned over tostada shells.
