Using an oblique cut, slice the 250 grams cucumbers into bite-sized pieces.
Add the cucumbers to a bowl and toss with ¼ teaspoon salt to coat evenly. Let the salted cucumbers rest for at least 20 minutes to allow them to sweat.
Drain off any accumulated water from the cucumbers.
Add the chopped 10 grams shiso leaves and 25 grams ume paste and toss to coat.
Plate and top the ume shiso cucumbers with ¼ teaspoon toasted sesame seeds.