Snap the head off, peel the shell off the body (leaving part of the shell at the tail end), make a cut down the back and the stomach and remove the dark veins (intestine).
Lightly beat egg whites with a whisk, and when they will be foamy, add the sifted flour, salt, black pepper and chopped parsley.
Mix gently, just to combine.
Heat the oil to 350 F (180°), dip the rice vermicelli for about 1 minute and drain well on kitchen paper.
Dip the prawns, in batches, in batter to coat.
Add prawns to the hot oil and deep-fry for about 2 minutes, flipping a couple of times, or until golden brown.
Arrange prawns on the crispy noodles and serve immediately.