1. Begin by making dashi, in a pan add a piece of kombu roughly the size of your hand then add 500 ml of water and soak for approximately 15 minutes to infuse. When ready add to the hob on a medium high heat until just about to boil. Just before removing from the heat add a handful of bonito flakes and leave infuse for another 15 minutes. Treat dashi like a cup of tea, you never want the stock to boil but you want to extract all the umami from the kombu and bonito flakes. When ready drain the stock into a bowl and set aside.
2. Now onto the dipping sauce, in a pan add 60 ml of sake and burn off all the alcohol until reduced by half. Next add 60 ml of mirin, 60 ml of soy, then add the dashi stock we made earlier followed by 2 tbsp of sugar and cook on a medium heat leave to simmer for around 10 minutes, when ready set aside. The sauce should be thin and transparent but yet leak umami.
3. Now to the prawns, to make straight tempura prawns we firstly need to remove the head and take off the shell of the prawn only leaving the tail of the prawn on. On the back of the prawn slice a thin line and remove the tract. After this is done turn over the prawn and make small slits with a knife all the way down the prawns belly, turn the prawn over and gently squeeze down each slit and you should hear a pop. The prawn should now be straight, set aside, now onto preparing the vegetables. For the vegetables slice into varius bite sized pieces and leave aside (its entirely up to you on how you cut the vegetables).
4. Now that the sauce and other ingredients are all prepared, onto the tempura batter. In a large bowl add 250g of plain flour then in a separate jug add 200ml of ice water, 1 whole egg, a pinch of salt then add to the flour making sure to mix roughly by still leaving raw flour inside the batter. The rough batter mix will ensure a crispier tempura.
5. Now let’s cook, add oil to a wok and bring the temperature up to around 160 degrees centigrade. Then prepare the vegetables and prawns by firstly dredging in plain four (this will help the batter stick). Next add to the batter and before frying add a drizzle of the batter to the hot oil and lightly fry. When the batter is separated add the prawns and vegetables in batches to the frothy tempura. When cooked repeat the process by adding the the batter first then the prawns and vegetables binding together with the batter. When each batch of tempura is cooked drain onto a wire rack to remove any excess oil.