Bring a large pot of salted water to a boil over high heat. Turn off the heat, add the shrimp, and poach until the shrimp are opaque and just cooked through, 2 to 3 minutes. Drain the shrimp and set aside until cool enough to handle, about 10 minutes.

Chop the shrimp into 1/2-inch pieces and place in a large bowl. Add the lemon juice, lime juice, tomatoes, red onion, jalapeño, cilantro, and salt, and toss to combine. Cover and refrigerate for at least 1 hour or up to 4 hours.

Just before serving, dice the avocado, add to the ceviche, and gently toss to combine. Serve with tortilla chips, if desired

Add TABASCO or canned Jalapeños for flavor