To make the dressing, mix the sriracha, oyster sauce and grated garlic in a bowl and keep aside.
Whisk the eggs well with a pinch of salt. Add the chopped prawns and Chinese five spice and beat well again.
Heat oil in a flat pan and pour in the egg mixture. Allow to cook well on one side before flipping over; cook on the other side till done. Roll the omelette and remove to a plate.
Garnish with bean sprouts, coriander leaves, ginger, fried shallots and drizzled generously with the dressing.