Start this recipe by greasing 2 small bowls generously with butter. These will be used as a mould to serve the rice 1 teaspoon oil in a wok over a high heat and swirl to coat. Add the beaten egg and cook quickly to scramble stirring constantly, for about 30 seconds. Transfer the egg to a plate and put aside. Add 1 tsp of oil to the wok and heat until steaming. Add the tiger prawns and king prawns to the wok, season well with salt and pepper and fry, tossing occasionally for only 1 to 2 minutes until cooked. Remove from the wok and put aside. Add the remaining tablespoon of oil to the pan and heat well before adding in the lemongrass, garlic, ginger and chilli. Cook quickly, tossing around for 1 minute. Add the fish stock pot, sherry and shitake mushrooms and cook for a further 2 minutes. Add the shrimp and continue to cook for 2 minutes. Stir in the cooked jasmine rice, soy sauce, spring onions, cashew nuts, lime juice and scrambled eggs, breaking up any large lumps. Season well with salt and pepper and stir in the chopped coriander. Next, arrange 3cooked tiger prawns into the bottom of the 2 bowls and immediately fill up the bowls with the prepared hot rice stir-fry. Press down slightly and leave to sit for a minute or two. When ready to serve, cover each bowl with a large plate and tip over, removing the bowl off. You should end up with a lovely dome-shaped rice stir-fry imbedded with the tiger prawns. Quickly arrange the remaining sliced spring onions on the top and a whole king prawn on each dome. Serve immediately with 2 wedges of lime on the side of each plate.