Wash 1 pound raw shrimp well, checking for veins, and then chop into small bite-sized pieces. Place in a large glass baking dish and spread out evenly.
Pour in 3/4 cup lemon juice, 3/4 cup lime juice, and 1/2 cup orange juice. Add more if needed to cover the shrimp fully. Place in the refrigerator for about 2 hours or until the shrimp is fully opaque but still tender. (Do not overmarinate or the shrimp may become rubbery.)
When the shrimp is cooked, add 2 roma tomatoes, 2 jalapenos, 1 large English cucumber, 1 avocado, 1/2 medium red onion, 2 cloves garlic, and 1/4 cup cilantro to a large serving bowl. Use a slotted spoon to transfer the shrimp to the serving bowl along with 1/4 cup of the citrus marinade. Gently mix until well combined.
Serve immediately with tortilla chips for dipping or return to the fridge for 1 hour to let the flavors blend together.
Notes
Cooked shrimp option: You can use cooked shrimp instead of raw shrimp if preferred. Since it is already cooked, only marinate it in the citrus juice for 15 to 30 minutes to soak up the flavor.Storage: Store leftover shrimp ceviche in an airtight container in the refrigerator. This recipe is best enjoyed the same day and should be eaten within 1 day for the best texture. The longer it sits, the firmer the shrimp will become and the softer the vegetables and avocado will get.