1. Wash crabs. Gently pull away round hard shell at top. Cut away grey fibrous tissue. Rinse inside of crab. Chop off claws and big nippers. Chop down centre of crab. Place crab in shallow dish.
2. Combine ginger and garlic in bowl, cook on HIGH for two minutes, add remaining ingredients, except shallots, cook on HIGH for three minutes, stir twice during cooking.
3. Pour chilli sauce over crab, sprinkle with shallots, cover, cook on MEDIUM for five minutes.