1. Please refer to Home Style Japanese Dashi Stock for how to make dashi stock.
The flavour of the dipping sauce is not as strong as in some other recipes. The ratio of dashi stock, mirin and soy sauce is 4:1:1 respectively. You could change this ratio to 3:1:1 if you prefer a stronger flavour.
2. I bought a small eggplant about 12cm (4¾”) long, 4cm (1½”) wide. If you can find shorter eggplants, you can use two and skip the step to halve the length, ie. the second cut in my recipe.
Common eggplant sold in Sydney is rather large, about 15-18cm (6-7”) long, 6-8cm (2½-3”) wide. This is not suitable for preparation as described above. If you can only find a large eggplant, you could simply slice it into 5mm (3/16”) thick bite sizes.
3. You can substitute enoki mushrooms with shiitake if you like. Then you won’t need yaki nori to tie the stems together. In the case of shiitake mushrooms, it will look prettier if you do not cover the entire mushroom cap with the batter, so that the colour will show when fried.
4. Shiso is a Japanese perilla, a herb with a quite distinctive fragrance. It has broad leaves of about 8cm x 6cm (3⅛” x 2⅜”). There are red shiso leaves as well as green shiso leaves, but the green ones are used for tempura. More details can be found in Wikipedia.
You can buy shiso leaves at Japanese grocery stores. You might find perilla leaves in Asian grocery stores or Asian vegetable shops, but they are most likely the Korean perilla leaves, which are larger and quite different from the Japanese perilla.
5. I used medium prawns about 40g (1.5 oz) each before removing head and shell. Any smaller than this would not be recommended. If quite large, you could reduce the number to two per serve and the cooking time would be longer.
6. Use vegetable oil or canola oil. You could also add a small amount of sesame oil to add flavour to the tempura if you like. Professional tempura chefs do mix sesame oil to the frying oil. Olive oil is not suitable.
7. It is extremely important to keep the batter cold. I measured the ingredients and then left them in the fridge overnight, even the flour.
The quantity (volume) of flour required to make the batter is the same as that of the egg mixture (water + egg). That’s why the flour is measured in volume, not in weight in the ingredients list. Depending on the size of the egg, you can adjust the amount of flour. If you are making a smaller quantity, you could just use an egg yolk.
8. If the vein does not come out by pulling it from where the head was, you can use a toothpick to remove the vein by piercing the middle of the back and lifting up the vein gently.
You do not make a slit along the back of the prawn to remove the vein when preparing for tempura.
9. I saved one third of the batter ingredients to be added after the carrots are fried. This is because by the time the carrot sticks are battered, the batter would have activated gluten a lot and become heavy batter, making crisp lightly battered prawn tempura difficult to achieve.
10. There are no rules as to what should be placed where, but when plating, try to give height with the prawns by leaning them against each other. After all, prawns are the king of tempura!
Grated daikon and ginger may be added to the dipping sauce before eating. You don’t have to add these, as it is yummy even without them.
Alternatively, you could serve all of the tempura on a large plate to share, accompanied by daikon and ginger in a separate bowl, with dipping sauce for individual.
11. To make vegetarian tempura, make it with vegetables and using konbu dashi stock (please refer to Varieties of Dashi Stock) for dipping sauce.