In a bowl, mix salt, white pepper, sugar, and five spice pepper together.
To prepare your crabs humanely, place them in the freezer for 1 hour to put them to sleep, or submerge them in an ice bath for 5 minutes.
Remove the upper shell of the crab, pick off the gills, which look like little fingers, and discard them. Clean the crab under running water and drain.
Place the crab on its stomach and chop the crab in 1/2 with a heavy cleaver.
Now chop each 1/2 into 4 pieces, chopping each piece after each leg.
With the back of the cleaver gently crack each claw - this makes it easier to extract the meat.
Heat the oil in a wok to 400 degrees F/200 degrees C, or until a cube of bread dropped into the oil browns in 5 seconds.
Dust the crab pieces with potato starch, shaking off the excess. Deep-fry the crab in batches for 3 minutes, turning over once, until golden brown.
Remove from the wok and drain on kitchen paper towels. Remove the oil, reserving 2 tablespoons, and clean the wok.
Heat the reserved oil in the wok, then add the shallots and garlic and fry until fragrant.
Return the crab to the wok and toss all ingredients together well, adding the salt and pepper seasoning mix to taste.
Serve with jasmine rice and finger bowl.