Rinse rice in a colander or strainer. Let drain well.

Bring about 600ml (2 1/2 US cups) water and kombu/kelp, if using, to a boil. Add salt and green peas. Cook peas for 3 minutes. (You'll saving the boiling water so don't drain it!)

Drain peas, but keep the water they were boiled in. Chill peas in ice water or running cold water and set aside. Let the water used for boiling cool until it's at least cool enough to touch. (If using kombu, leave it in the water)

Add drained rice to a heavy pot (if using kombu, add that too). Measure out 540ml (2 1/3 US cups) of the water from boiling. If you don't have enough, add regular water until you do.

*If using rice cooker, just add everything into the rice cooker and push start and skip to step 6!

Cover pot with lid and bring to a simmer over medium. Once steam starts to rise from the pot, turn heat to low and simmer for 23-25 minutes. Stop heat and let sit, with lid, for another 15 minutes.

After the rice is finished, add peas to the rice and fold in to distribute evenly. Garnish with sesame seeds if you like. You can also season with just a bit of salt and pepper too :)