Make the marinade by mixing together the salt, white pepper, cornflour and sesame oil. Toss the prawns in to coat, let sit for 20 minutes.
Meanwhile, slice 1/4 of the pineapple along the length, leaving the bulk of the pineapple attached to the leaves. Carve out the pineapple with a knife and then dice. Soak the pineapple in lightly salted water.
Preheat the oven to 150 C / Gas 2.
Heat a large frying pan with 1 tablespoon oil over high heat. Stir-fry the prawns until fully cooked, 3-4 minutes, set aside.
Heat the same pan with 1 tablespoon oil over high heat. Stir-fry the garlic until fragrant, about 2-3 minutes. Add the onion and salt and cook until soft, about 3-4 minutes. Add the green peppers, seafood sticks and fry until the pan becomes dry, 2-3 minutes. Add the prawns back into the pan and stir to mix. Set the ingredients aside.
Heat the same pan with 2 tablespoons oil over high heat. Stir in 1/3 of the egg and rice and stir quickly. Add some salt, then stir in 1/2 of the egg and fish sauce. Mix well. Add the remaining egg, Thai basil, pineapple and all of the cooked ingredients back into the pan and transfer to the pineapple boat.
Bake the pineapple and fried rice for 10 minutes. Garnish with roasted cashews and serve hot.
Thai basil leaves are available in Chinese/Oriental speciality stores.