Season the chicken: In a bowl, toss the chicken with 1 tablespoon Cajun seasoning, smoked paprika, garlic powder, onion powder, salt, and pepper until evenly coated.
Sear the chicken: Heat 1 tablespoon olive oil in a large skillet over medium-high. Add chicken in a single layer. Cook 4–6 minutes, stirring once, until browned and just cooked through.
Transfer to a plate.
Sauté the aromatics: Lower heat to medium. Add the remaining 1 tablespoon olive oil and the butter. Stir in onion and bell pepper.
Cook 4–5 minutes until softened and lightly browned. Add garlic and cook 30 seconds, just until fragrant.
Deglaze and build the sauce: Pour in chicken broth, scraping up browned bits. Stir in remaining 1 tablespoon Cajun seasoning.
Simmer 2 minutes to reduce slightly.
Make it creamy: Reduce heat to medium-low. Add heavy cream and cream cheese. Whisk or stir until smooth and slightly thickened, 2–3 minutes.
Stir in Dijon, lemon zest, and Parmesan if using. Taste and adjust salt.
Return the chicken: Add the chicken and any juices back to the skillet. Simmer 1–2 minutes so the flavors meld.
Finish with lemon juice for brightness.
Cook the cauliflower rice: In a separate large nonstick pan, warm a drizzle of oil over medium-high. Add riced cauliflower with a pinch of salt and pepper. Cook 4–6 minutes, stirring often, until tender and steam has mostly cooked off.
Keep it fluffy, not soggy.
Serve: Spoon the creamy Cajun chicken over the cauliflower rice. Garnish with parsley or green onions. Enjoy hot.