1 pound medium-small raw shrimp, peeled and deveined
2 Tbsp salt
3/4 cup lime juice (juice from 4-6 limes)
3/4 cup lemon juice (juice from 2-3 lemons)
1 cup finely chopped red onion
1-2 jalapenoes, ribs and seeds removed, minced
1 cup chopped fresh cilantro
1 cucumber, peeled finely diced
2-3 roma tomatoes, finely diced

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 with a slotted spoon and place into a bowl of ice water to stop the cooking.

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.

Mix in the chopped red onion, jalapenoes & tomatoes. Refrigerate an additional half hour.

Right before serving, add the cilantro, cucumber & avocado. Toss to combine and serve as is, with chips or on top of tostadas.