Slice each chicken breast horizontally to create thin cutlets.
Pat the chicken dry with paper towels.
Mix salt, pepper, paprika, garlic powder, onion powder, and Cajun seasoning in a small bowl.
Rub the seasoning evenly over both sides of the chicken.
Rinse the rice twice under cold water.
Add rice, water, and salt to a pot and bring to a boil uncovered.
Reduce heat to low, cover, and simmer for 18–20 minutes.
Turn off heat and let rice steam covered for 5 minutes, then fluff with a fork.
Heat olive oil in a large skillet over medium-high heat.
Add chicken in a single layer and cook 5–6 minutes per side until golden and internal temperature reaches 165°F.
Remove chicken from skillet and let it rest.
In a clean skillet, melt butter over medium heat.
Add diced onion and cook until soft and translucent.
Stir in garlic and cook for 30 seconds.
Pour in half and half and whisk gently.
Add paprika, Cajun seasoning, salt, and black pepper.
Let the sauce simmer gently until slightly thickened.
Stir in shredded cheese and mix until smooth and creamy.
Slice rested chicken against the grain.
Plate rice, top with chicken, and spoon creamy Cajun sauce over the top. Serve immediately.