「PREP」Remove the seeds from the umeboshi and crush with a fork. Keep a little bit aside to use as a garnish.
Mix the minced chicken meat, umeboshi and (A) together in a bowl and knead well.
Heat up the vegetable oil in a skillet over medium heat. Shape the meat mixture into bite-size balls and put in the frying pan. When the colour changes, flip the meatballs, add the sake and cover with a lid. Cook for two minutes over low heat.
Cut the shiso leaves into shreds. Put the meatballs on a plate and garnish with the leftover crushed umeboshi and the shredded shiso leaves.