Clean the crab well. Heat oil in a large saucepan, stir-fry garlic, onion, lemongrass and chili over high heat for a few minutes.
Pour fish sauce, lime juice and water into the pan and bring to the boil. Carefully place crab in saucepan. Cover with a tightly fitting lid. Cook over a medium high heat for 10-15 minutes until the crab is cooked.
Place crab on a serving platter. Add spring onions to the pan, heat cooking liquid until reduced to about ¼ cup and pour over the crab.
Arrange bean shoots over the hot crab, sprinkle liberally with deep-fried shallots and serve with extra lime juice and dipping sauce.
