Steps

1. Gently wash the shiso leaves under running water and trim off any tough stems. Drain well in a colander. (Key Tip!) Wash the leaves gently to avoid bruising. If using homegrown shiso, make sure to thoroughly wash away any insects or dirt.
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2. Bring water to a boil in a frying pan, add 1 tsp of salt, and quickly blanch the shiso leaves.
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3. Immediately turn off the heat after blanching the shiso leaves and plunge them into cold water to cool down.
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4. Remove the shiso leaves from the cold water and squeeze out the moisture thoroughly.
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5. Trim off the thicker stems with scissors and finely chop the squeezed shiso leaves.
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6. In a frying pan, combine 3 tbsp of soy sauce, 1.5 tbsp of mirin (sweet rice wine), 1.5 tbsp of cooking sake (rice wine), 1.5 tbsp of sugar, 1.5 tbsp of white roasted sesame seeds, and a handful of bonito flakes (katsuobushi). Bring to a boil over heat. (Key Tip!) Using ground sesame seeds will improve absorption.
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7. Prepare the dried red chili pepper if using. Remove the seeds and slice into rings with scissors. (Key Tip!) Omit if children will be eating the dish.
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8. Add the chopped shiso leaves and the sliced dried red chili pepper (if using) to the boiling sauce. Simmer until the liquid is absorbed. (Key Tip!) Leftover red shiso after making juice can also be used. In that case, double the seasonings and add more white roasted sesame seeds and bonito flakes (katsuobushi).
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9. Transfer the finished tsukudani to a clean storage container and refrigerate. (Key Tip!) Ensure moisture is thoroughly evaporated and the seasoning is strong for better preservation. If using clean chopsticks to remove the tsukudani, it can be stored in the refrigerator for about 1 month.
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