Add all of the dry ingredients and mix. Do not thoroughly mix the egg.
Heat the oil for deep frying at a slightly low temperature (160℃). To cook thin ingredients, such as shiso leaves, lightly coat the back in flour, then dip in the batter and deep fry.
Next, fry the starchy vegetables, such as potatoes, then chicken or other meats. When frying potatoes, start at a low temperature, then increase to a high temperature for a crispy finish.
Next, at a high temperature, lightly coat the fish in flour, then the batter, then deep fry at a slightly high temperature. Seafood should be deep fried very quickly.
These are the ingredients that need to be cooked quickly. As long as you don't wrap the tempura in plastic wrap, even shiso leaves remain nice and crispy.
I recommend lightly reheating in an oven, not in the microwave. This will make them crispy.
Story Behind this Recipe
This is a tempura batter recipe that I created after a lot of trial and error. It's popular in my home, since the tempura doesn't become stale even a while after serving. I recommend this recipe for people with family members who eat at different times.
After preparing the ingredients to deep fry, chill them in the refrigerator. Katakuriko will sink to the bottom of the dredge mixture, so mix it up before dredging. To make even crispier batter, substitute the cake flour with katakuriko. Katakuriko is an indispensable ingredient when making tempura that stays crispy even after some time.