Heat the olive oil in a large pot over medium heat.
Season the diced chicken with Cajun seasoning, salt, black pepper, and paprika.
Cook the chicken for 5–7 minutes until golden and fully cooked. Remove from the pot and set aside.
Melt the butter in the same pot and sauté the garlic for about 1 minute until fragrant.
Stir in the orzo and toast it for 1–2 minutes.
Pour in the chicken broth and bring to a gentle simmer.
Cook, stirring occasionally, until the orzo is tender and most of the liquid has been absorbed.
Reduce the heat to low and stir in the heavy cream and Parmesan cheese until smooth and creamy.
Return the chicken to the pot and gently mix everything together. Add spinach or bell peppers if desired.
Simmer for another 2–3 minutes until heated through.
Garnish with chopped parsley and serve your One Pot Cajun Chicken Alfredo Orzo immediately.