Here's the Tempura Batter Recipe I use (when I do a Tempura batter)
INGREDIENTS
1 cup all-purpose flour
2 tablespoons cornstarch
1⁄2 teaspoon salt
1 cup ice water (don't let it freeze, but best to put it in the freezer first to ensure it's plenty cold enough)
1 egg yolk
2 egg whites, stiffly beaten
DIRECTIONS
Stir together flour, cornstarch and salt.
Make a well in the center.
Combine ice water and egg yolk, beating with a fork or whisk until frothy.
Add all at once to dry ingredients.
Slowly stir just until moistened; DO NOT over stir,a few lumps should remain.
Fold in beaten egg whites.
Add 1 teaspoon salt.
Use batter immediately.
Heat oil or shortening to 400°F.
Dip fish, shrimp or vegetables into batter, swirling to coat.
Fry a few pieces at a time 2 to 3 minutes or until golden brown.
Drain on paper towels or use a drip tray.
Note: IF doing vegetables make sure your vegetables are very very dry so the batter will stick better.
Also, as I have said in other posts about deep frying, if you’re doing a large batch, just blanche whatever it is you’re frying up, remove it from the oil and let it rest on a drip tray until you’ve blanched all of it, then put back into the oil to finish. (Food that is deep fried will float when it is cooked through.)