1.Shell prawns, leaving tail intact. Remove back vein. With sharp knife cut deeply along back of prawns, but do not cut right through. Gently pound prawns out flat with small meat mallet or rolling pin.
2.Drain crab, remove any fibrous tissue. Chop shallots and celery very finely. Place crab, Chinese pickles, shallots, celery, egg white, cornflour, sherry and soy sauce into bowl. Mix well.
3.With small spatula press approximately one tablespoon of crab filling onto flattened-out prawn. Repeat with remaining prawn and crab mixture. Gently coat prawns with flour seasoned with salt. Make sure that you keep prawns crab side up, this is important as filling could fall off prawns. With two forks, coat prawns with combined beaten eggs and milk, then press bread crumbs firmly onto prawns. Place in single layer on to tray, refrigerate until ready to deep-fry.
4.Place into deep hot oil, fry until golden brown and cooked through, approximately two minutes. Do not have oil too hot or prawns will brown too quickly and not cook through. Drain on absorbent paper.
5.To make sate sauce, heat oil in wok or frying pan, add peeled and very finely chopped onion, saute gently until onion is transparent. Add curry powder, saute for one minute. Add soy sauce, sherry and sugar, saute for two minutes stirring constantly. Add cream, stir until combined, bring to boil, reduce heat, simmer uncovered for two minutes or until slightly thickened. Pour sauce into four individual serving bowls, dip prawns into sauce to eat.
6.Serve with prepared sate sauce.