Rinse the rice and place in to a large pan. Add the coconut milk and place on a relatively high heat. Bash the lemon grass with a rolling pin or pestle so that it looks squashed and put in to the rice so the flavour can infuse. Add the salt and water. Stir regularly, you'll notice that as it cooks the rice really enjoys sticking to the bottom of the pan. When a gentle boil has been reached turn the heat down to the lowest setting and cook until you can tell, by tasting it, that it is about 5 minutes away from being cooked. At this point remove the pan from the heat, stir, place a tight lid on to the pan and set aside.
While the rice is cooking dry-fry the cashews in a large frying pan. When they are toasted, but not burnt, remove nuts from the pan and set aside. Add the olive oil, onions and garlic to the same pan and soften gently on a low heat. Add the mange tout, pineapple, soy sauce, toasted cashews and spring onions.
When the rice is cooked through fluff it up and serve on to warmed plates. Add the vegetable mix to the top of the bed of rice. Sprinkle with the chopped coriander and garnish/squeeze with the quarter of lime. Serve immediately.