1 In a large pot, bring to a boil 4 quarts of water, salted with 2 Tbsp salt. Add the shrimp and cook for 1 minute to 2 minutes max, depending on size of shrimp. (Over-cooking the shrimp will turn it rubbery.) Remove shrimp  and place into a bowl.

2 Drain the shrimp. Cut each piece of shrimp in half, or into inch-long pieces. Place shrimp in a glass or ceramic bowl. Mix in the lime and lemon juice. Cover and refrigerate for a half hour.

3 Mix in the chopped red onion and serrano chile. Refrigerate an additional half hour.

4 Right before serving, add the cilantro, cucumber, and avocado.

Serves 4-6