add 1 cup rice to a fine mesh strainer and rinse, using your hands to agitate the grains, until the water runs clear. This gets rid of the extra starch so your rice isn’t mushy. Add rice to a medium pot along with 1 ½ cups water. Cover and turn the heat on high. Once the water starts to simmer rapidly, reduce the heat to low and simmer gently, covered, for about 12-15 minutes, or until the water is evaporated and rice is cooked. Don’t remove the lid until the timer goes off!
In a large bowl, whisk together the soy, sesame seeds, sesame oil, vinegar, ginger, and 1 cup scallions. Add the tuna and toss to coat, breaking the tuna up into chunks.
In a medium bowl or container with a lid, add the cucumbers, vinegar, and soy sauce and toss to coat. Let sit for at least 10 minutes (overnight is best).
Assemble your bowls! Add a scoop of rice, tuna, cucumbers, veggies, and avocado. Spoon some of the liquid from the cucumbers over the rice and veggies. You can top with more scallions, sesame seeds, and some sriracha, if you’d like.