Preheat the oven to 375°F (190°C). Using a knife and cutting board, carefully cut off the tops of the bell peppers and remove the seeds and membranes. Set aside.
In a skillet, heat olive oil over medium heat until shimmering. Add minced garlic and sauté until fragrant, about 30 seconds. Add chopped shrimp and cook until they turn pink and opaque, about 2-3 minutes. Stir in crab meat and cooked rice, then season with salt and pepper. Cook for another minute, until ingredients are combined and heated through.
4 pieces bell peppers
Fill each hollowed-out pepper with the seafood and rice mixture, pressing gently to pack. Place the stuffed peppers in a baking dish upright, ensuring they sit stably.
4 pieces bell peppers
Sprinkle shredded cheese over the top of each stuffed pepper if desired. Bake in the preheated oven for 20-25 minutes, until the peppers are tender and the cheese is golden brown.
4 pieces bell peppers
Remove from oven and let cool slightly. Serve hot, garnished with fresh herbs if desired.