1Place shrimp into a flat dish; cover with lime juice. Chill shrimp in refrigerator until tender, at least 3 hours. Drain lime juice.
2Mix tomato, cilantro, green bell pepper, green onion, jalapeno pepper to taste, garlic, salt, and pepper in a bowl; add shrimp and avocado and stir. Chill in refrigerator until flavors blend, about 1 hour.