Place the chopped romaine lettuce on a platter orbowl. Add remaining ingredients in rows over the top of your lettuce: chopped tomatoes, sliced redonion, sliced cucumber, cajun shrimp, avocado and corn.
To make the dressing, in a small bowl, whisk together oil, garlic, lemon juice,cilantro/parsley, salt and pepper. Drizzle dressing over the shrimp avocado salad then toss to combine and serve.