Stir together Cajun seasoning ingredients in a small bowl. Set aside.
Add 2 tablespoons of olive oil to a large skillet over medium heat. Stir in cauliflower rice, minced garlic, and half of the Cajun seasoning. Cover and cook for 5 to 7 minutes, stirring occasionally. Cauliflower should be tender and close to done.
While cauliflower is cooking, combine shrimp, 1 tablespoon oil, and remaining 1/2 of the Cajun seasoning in a bowl or Ziploc bag. Shrimp should be coated in seasoning.
Stir seasoned shrimp into the cauliflower rice. Cover and cook until shrimp is pink and cooked through, about 4 to 5 minutes.
Stir chopped parsley or green onions into your finished dish before serving.