Clean and prepare the avocado, mackerel, barley, green onion, and beans.
Wash and soak the barley and beans, then place them in a pot and cook the rice.
When the rice is nearly done, add the mackerel (if using canned, remove some of the oil) and chopped green onion.
Once the rice is cooked, dice the avocado and place it on top, then mix together.