Step 1

Discard the seeds from ume and mince the ume flesh.

Step 2

Roll up the shiso leaves and cut them into julienned strips. Add minced ume and shiso to the rice.

Step 3

Add toasted sesame seeds and combine everything together.

Step 4

First, prepare a bowl with water. Wet both of your hands with water. This helps preventing the rice from sticking to your hands.

Step 5

Dip 2-3 fingertips in kosher salt and spread all around your palms.

Step 6

Scoop out a handful of rice into one hand.

Step 7

Gently press the rice to form into a triangle shape with your hands. I use three fingers (thumb, index finger, middle finger) to make a triangle corner. Your hands should be just firm enough so the onigiri doesn’t fall apart. You don’t want to squeeze the rice too tight.

Step 8

If you have never tried making onigiri, I have a detailed step-by-step onigiri tutorial here. Please read the instruction first before the prep.

Step 9

If you want to keep the leftover onigiri, you can wrap the finished onigiri (in plastic wrap) with a thick kitchen towel to seal in the moisture when stored in the refrigerator. Rice gets hard and dry in the refrigerator. Hopefully, with this easy trick, your onigiri will be cool enough to stay safe.