Combine chicken, soy sauce, brown sugar, salt, Shaoxing rice wine, and 1 teaspoon cornstarch in a bowl. Mix and set aside to marinate for 15 minutes.
Place shrimp in a separate bowl and season with salt, black pepper, and 1 teaspoon sesame oil. Stir in remaining 1 teaspoon cornstarch and set aside for 15 minutes.
Remove 1/4 of the pineapple lengthways, leaving the green leaves intact for presentation, if you like; scoop out the pineapple flesh using a spoon. Chop pineapple flesh into small pieces and set aside. Place hollow pineapple on a baking tray.
Preheat the oven to 350 degrees F (180 degrees C).
Heat remaining 1 teaspoon sesame oil in a wok over high heat. Add garlic, carrots, and bell peppers and cook for 3 to 4 minutes. Stir in chicken and cook until browned, 4 to 5 minutes. Add prawns and cook for 1 to 2 minutes; add cooked rice and pineapple, mixing well to combine. Stir in beaten egg until cooked through.
Spoon fried rice into prepared pineapple shell; bake in the preheated oven until piping hot, about 10 minutes. Bring pineapple to the table and let everyone help themselves!