Shrimp, haddock, vegetables (egg plant, zucchini, kabocha squash). You can season it with spices or seasonings if you like.
In a mixing bowl, combine the cake flour, cornstarch, salt and baking powder.
Heat vegetable oil in a pan until very hot, but not smoking (about 375 degrees F).
Whisk the egg and cold sparkling water together in a medium mixing bowl until mildly foamy.
Add the flour a little at a time, stirring with chopsticks just to combine, and make a loose batter with the consistency of heavy cream. When mixing the ingredients together, don’t overmix the batter, it is ok to have some lumps. Use a couple of chopsticks to mix the ingredients together without overmixing them.
(optional) Dredge the items in additional cake flour to help the batter stick evenly on tempura.
Dip the items in the batter quickly, shake them out, then put them into the hot oil, fry them in 350°F oil. To keep the oil temperature from dropping too low, do this in batches. Avoid overcrowding the pot.
Cook for 2 to 3 minutes per side, until the batter is golden brown.
Remove cooked tempura from the oil and place it on a cooling rack on a baking sheet.
Continue until you've used up all of your ingredients. When you've finished frying everything, keep the remaining warm in an oven set to 200 degrees Fahrenheit until ready to serve.
Serve with Tempura dipping sauce.