I added umeboshi and shiso leaves to tartare sauce and it became such a refreshing sauce! It's a bit of a different taste than the usual tartare sauce.
When I lived in Miyazaki Prefecture, there was a restaurant with delicious chicken nanban that used this umeboshi tartare sauce. I wanted to eat it again, so I tried making it.
Be sure to thoroughly squeeze out the moisture of the cucumber pickles. Mix in the boiled egg after letting it cool.
Enjoy Japanese food around the world.