1. Discard the innards of crabs and cut into halves, wash thoroughly and drain well. Trim prawns and leave the shells intact, rinse and drain well.
2. Scald scored squids in boiling water until they curl up. Remove and drain well.
3. Fill a wok with half-full of oil, deep-fry crabs and prawns separately until cooked. Remove and set aside.
4. Heat 3 tbsp of oil, add in sliced garlic, chopped chilli and Ingredients B and bring to a boil. Add in remaining Ingredients A and stir well.
5. Stir in Corn Flour Solution and serve.