Peel the shrimp, breaking the shell away at the tail.
The tail remains attached to the shelled shrimp.
Holding the shrimp flat on a cutting board, parallel-cut ½ inch deep to expose the vein and partially butterfly the shrimp. Remove the vein. Marinate the shrimp 10 minutes or more. Mix the batter.
Heat the oil in a wok to moderate (350 degrees). Dip the shrimp into the batter. With long chopsticks, lift them out one by one, letting the excess batter drip away. Slide them into the oil one at a time to keep them from sticking together.
When the shrimp are crisp and lightly browned (large shrimp take about 3 minutes, smaller ones 2 minutes), lift them from the oil with a strainer. (The oil may be cooled, strained, and stored for reuse to deep-fry seafood.)
An attractive and simple presentation is to fry a handful of shrimp chips to serve as a bed for the shrimp. A whole shrimp, head and tail on, makes a dramatic garnish.