*Dashi is a Japanese stock that is important for the depth of umami. You can make dashi in several ways. The easiest is to use the dashi powder (simply add to water to make dashi) or the dash sachets (boil the sachets with natural ingredients in water to make dashi). Follow the manufacturer’s instruction for each product to make 350ml dashi stock.
Make light vinaigrette by adding vinegar, soy sauce, mirin, maple syrup to dashi stock, then mix well.
Prepare the vegetables. Slice onion very thinly. Slice ginger very thinly and cut into fine strips. Cut red pepper in half and remove the core, then cut into 1cm strips. Remove the seeds from red chilli and slice thinly. Put them aside.
Cut each salmon fillet in half, then cut into 1.5cm slices. Cut each slice into 5cm length. You should end up with 5cm x 1.5cm strips.
Prepare salmon. Add katakuriko (potato starch powder) in a bowl and place the salmon strips. Coat each salmon strips in the katakuriko by shuffling them by hands several times.
Cook salmon. Add oil in medium sized frying pan to about 1.5-2cm deep and heat to 180°C. Take the salmon strip one by one, knock it on the inside-wall of the bowl several times to dust off the excess potato starch, then put it in the oil to cook. Cook 5-10 pieces in a batch depending on the size of the frying pan but make sure you have plenty of space for each piece to move freely. If it’s overcrowded the oil temperature will reduce too quickly, resulting in the sad soggy salmon. Cook for 3-4 minutes or until they are very crispy. Turn them around once halfway. Repeat the process for the rest of the salmon. Place the cooked salmon on a rack or kitchen towel. **Tips to ensure the crispiness: while frying: (1) remove the white starch powder accumulated at the bottom of the frying pan along with the ones that are floating in the oil with a heat resistant ladle or spoon with holes. They will block the oil from heating. (2) monitor the temperature and control the heat so it doesn’t drop below 170°C
Add the vinaigrette to a bowl or container then place the salmon. Add the onion, ginger, red pepper and chilli on top and gently press them down with a clingfilm. Store in the fridge for 2 hours to overnight.