1. Preheat your oven to 375°F (190°C). Cut the tops off the bell peppers and remove the seeds. Set aside.
2. Heat olive oil in a skillet over medium heat. Sauté onion and celery until softened, about 5 minutes.
3. Add shrimp to the skillet and cook until pink, about 2-3 minutes. Stir in Cajun seasoning, smoked paprika, and cooked rice. Mix well.
4. Add diced tomato, salt, and pepper to the mixture. Cook for another 2 minutes, then remove from heat.
5. Stuff the bell peppers with the rice and shrimp mixture and place them in a baking dish.
6. Bake for 25-30 minutes until the peppers are tender.
7. Garnish with fresh parsley and serve hot.