Toss the shrimp with Cajun seasoning, salt, and pepper.
Heat half of the oil in a pan over medium heat. Add the shrimp and cook for five minutes, stirring occasionally, until cooked through.
In a bowl, whisk together the remaining oil, lemon juice, salt, and pepper. Add the romaine, tomato, cucumber, and chickpeas, and toss to combine.
Divide the salad and shrimp evenly between plates. Top with tzatziki and enjoy!