In medium bowl combine the shrimp and Cajun seasoning. In a large skillet, heat the oil over medium heat. Add the shrimp and cook about 3 minutes, then add the garlic and red pepper flakes and cook until shrimp are cooked through, about 4 to 6 minutes.
Meanwhile, steam the corn kernels for 3 to 4 minutes. Let the shrimp and corn cool to room temperature. (Note: Recipe #304627 is the easiest and best method.).
In a large serving bowl, combine the shrimp, corn, tomatoes, roasted red pepper if using and parsley. In a small bowl, combine all the dressing ingredients and add to the salad. Mix well and adjust seasoning if needed. Serve at room temperature.