Prepare the shrimp for the mango shrimp salad. Boil water for cooking. Take twice as much water as seafood. Add salt and put the shrimp in boiling water for 2 minutes. It is important not to expose them to prolonged heat exposure so that the meat does not lose its tenderness and juiciness. Then let the shrimp cool and peel them.
Make the mango avocado salad dressing. In a small bowl, combine the olive oil, lime juice, salt, and pepper. Then whisk the ingredients thoroughly with a fork or whisk.
Assemble the salad. Place the lettuce, cherry tomatoes, avocado and mango in a large, deep salad bowl. Add the shrimp (chopped if desired) and onion. Dress the salad with the olive mixture and toss gently.