2 blue crab, 2 stalks of spring onions, some ginger, 4 cups of oil.
(1) 4T potato starch, 1T Shaoxing wine.
(2) 3T sweet bean paste, 1T Shaoxing wine, 1T ketchup, 1T sugar, some ground white pepper, 1 cup of water.
1. Put each crab on the counter with its back facing down; Insert a knife through its abdomen and hold it till the crab has stopped moving; Remove the reeds/strings; Separate the carapace from its body by lifting it; Discard the gills, the guts and the gizzard in the lower center part of carapace; Scrub the crab with a small brush to discard the dirt; Rinse and drain; Cut each half into 3 pieces; Cut pincer into halves; Keep the carapace in whole; Wipe dry; Marinate in seasoning (1) briefly.
2. Peel, rinse and mince ginger; Rinse and dice spring onion.
3. Add 4 cups of oil to a wok; Bring to the boil over a high heat; Turn to a low heat; Jiggle the crab in the oil over a high heat for 1 minute; Remove and drain.
4. Set the oil aside, leaving 2T oil; Heat the wok over a high heat; Stir-fry minced ginger over a high heat till fragrant; Add seasoning (2) and stir-fry over a high heat till fragrant; Return the crab to the wok; Stir-fry over a high heat till the sauce has thickened; Garnish with spring onion. Ready to serve.
After separating the carapace from the crab's body, it is important to discard the gills, guts and the gizzard completely, and scrub the crab thoroughly with a small brush, so that the mud and dirt would not get into the sauce, affecting the taste and even the health.