In a bowl, toss the chicken pieces with Cajun seasoning. Heat olive oil in a large skillet over medium-high heat. Add chicken and cook for 5-7 minutes, until browned and cooked through. Remove from skillet and set aside.

In the same skillet, add the chopped onion and bell pepper. Cook for 4-5 minutes until softened. Stir in the minced garlic and cook for 1 more minute until fragrant.

Add the dry orzo to the skillet. Stir constantly for 1-2 minutes to toast it lightly.

Pour in the chicken broth and undrained diced tomatoes. Bring to a simmer, then reduce heat to low, cover, and cook for 10-12 minutes, until orzo is al dente and has absorbed most of the liquid.

Stir in the heavy cream and grated Parmesan cheese until the sauce is smooth and creamy. Return the cooked chicken to the pan. Stir to combine and heat through. Season with salt and pepper to taste. Garnish with fresh parsley before serving.