This is a light dinner, maybe too light.
Cod and shrimp. A tempura dipping sauce is prepared first then a tempura batter.
Tempura is about ice-cold battered items dropped into hot oil for dramatic splatter. The coating is light. I've seen tempura cooks dribble cold tempura batter directly onto frying items already battered to extend the splattered batter patterns frying in the oil to somewhat resemble insect legs or other bizarre extensions of pure batter. You would want those creative splatter extensions to have some substance, delicate, but still sturdy enough to hold. That is not done here.
I wanted rice flour included in the batter but that is not necessary. Rice kernels were processed to dust in a coffee bean mill. This batter has egg which isn't necessary either. The batter also has corn starch along with all purpose wheat flour. So three types of powders where you can get by with wheat flour alone. See how that would change things? The batter is lightened with cold club soda. It could have as easily been tonic, Seven-up, beer, water with scant baking powder -- anything to get light bubble action going. Too much bubble action and the batter fries to light crisp foam. The batter must be cold so ice cubes are not out of the question. Ice cold battered items into hot oil is what Tempura is about.
Tempura dipping sauce:
* 1 cup bonito dashi. [bonito flakes boiled briefly in tap water then the flakes strained out after one minute or so]
* 1/4 cup soy sauce
* 1/4 cup mirin
* 2 level tablespoons sugar
* 1/2 teaspoon powder ginger
* 1/8 teaspoon chile powder flakes
Tempura batter:
* 1/4 cup white rice flour
* 2 level tablespoons corn starch
* 2 heaping tablespoons wheat flour
* 1/2 teaspoon salt
* 1/4 teaspoon white pepper
* 1 egg whisked
* 1 bottle club soda
Lightly coat items with thin batter then deep or shallow fry in vegetable oil at 350℉/175℃ until light golden brown. The cold seafood pieces cook within a minute.