Though the word tempura is Japanese, the technique likely originated with Portuguese missionaries to Japan, according to "The Oxford Companion to Food." Tempura consists of bite-sized pieces of fish and vegetables, lightly battered and fried. Professional cooks typically straighten shrimp used in tempura for presentation -- the shrimp remain straight after frying. Add a few extra minutes to the preparation time so that your tempura shrimp achieve this appearance.
Peel and devein the shrimp, but leave the tail intact.
Make three shallow, equally spaced horizontal cuts along the underside of each shrimp. Turn the shrimp over.
Press down firmly on the shrimp, moving from one end to the other, until the shrimp is completely straight and roughly twice its original length.
Batter and fry the shrimp immediately in a wok, deep fryer or saucepan filled one-third full of oil, or store them in the refrigerator until you are ready to fry them.