Peel the cucumber, cut it into fine slices or slice it. Peel ginger and dice very finely. Carve chilli lengthwise, remove seeds, chop finely. Peel onion, cut into small cubes. Mix vinegar, lemon juice, salt, pepper, sugar, chilli and ginger.
Add 4 tablespoons of oil. Mix the marinade, cucumber and onion and leave to stand. Season to taste again before serving, season if necessary. Grind the macadamia nuts and mix with breadcrumbs. Season mixture with salt and pepper.
Beat the eggs. Peel prawns down to the tail fin, remove intestines. Wash shrimps and pat dry. Turn one after the other in flour, egg and nut mixture. Fry in 4 tablespoons of oil over medium heat for about 8 minutes, turning.
Add some more oil if necessary. Serve the salad and prawns garnished with parsley and lemon slices.