Chop the lettuce, cucumber, and radish, slice the avocado and pay out on a serving dish.
In a blender combine the avocado, tahini, sour cream, garlic, parsley. salt and pepper. Blend to combine if the dressing is too thick you can thin it out with water or cream, set aside.
To make the Cajun seasoning combine garlic powder, onion powder, oregano, cayenne, chili powder, paprika and salt. Mix to combine and sprinkle over the shrimp. In a saute pan over medium-high heat, heat the oil. Add in the seasoned shrimp and cook until pink, 4-5 minutes, depending on size.
To the salad with the Cajun shrimp and drizzle with the tahini dressing toss to combine, and serve.