Cut the tops off the bell peppers and remove the seeds and membranes. If needed, slice a thin layer off the bottom to make them stand upright. Set aside.
Cook the Vegetables:
In a large skillet, heat the olive oil over medium heat. Add the chopped onion, celery, and red bell pepper. Sauté until the vegetables are soft, about 5 minutes. Add the garlic and cook for an additional minute.
Prepare the Filling:
In a large bowl, combine the cooked rice, cooked crab meat, and chopped shrimp. Add the sautéed vegetables, mayonnaise, Parmesan cheese, Old Bay seasoning, paprika, salt, black pepper, and cayenne pepper (if using). Mix well to combine.
Stuff the Peppers:
Spoon the crab and shrimp mixture into the prepared bell peppers, pressing down lightly to pack the filling.
Bake the Peppers:
Place the stuffed bell peppers in a baking dish. Add about 1/4 inch of water to the bottom of the dish to help steam the peppers. Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes.
Finish and Serve:
Remove the foil and bake for an additional 10-15 minutes, or until the peppers are tender and the filling is heated through. Drizzle with lemon juice and sprinkle with chopped parsley before serving.
Enjoy:
Serve the crab and shrimp stuffed bell peppers hot, garnished with additional parsley if desired.
