This Singapore dish is a classic and, like all classics, it is superb. Serve it with plain rice. Boil a large pot of water and drop in 4 green blue swimmers. Boil them rapidly for 4 minutes then tip the contents of the pot into a colander to drain. When cool enough to handle, chop crabs into quarters with a cleaver or large knife, leaving legs attached to body. With a hammer. gently crack the claws and areas of harder shell. Put 3 teaspoons tamarind pulp to soak in 0.75 cup boiling water. Finely chop 2 onions, grate 5 cm piece fresh ginger, finely slice 2-3 birdseye chillies (or to taste) and chop 3 green (spring) onions. Mix 2 teaspoons cornflour with a little water. In a large wok or pan, heat 3 tablespoons of oil and stirfry onion, ginger and two third of the chopped chillies for a couple of minutes. Add crab pieces and strained tamarind water, lower heat and simmer for 3-4 minutes. Lift the crab out onto a serving dish and to the mixture in the wok add 3 teaspoons sugar and 2 of tomato paste. Stir, add dissolved cornflour and stir again until the mixture thickens. Pour over the crab, garnish with the rest of the chillies and the spring onions and serve. From an article by Meryl Constance in The Sydney Morning Herald, 0. 298685782556.75. Courtesy Mark Herron.