Prepare the rice.
Drain the oil from the canned tuna and set aside.
Wash all vegetables (cucumber, carrot, spinach, leafy greens, etc.) thoroughly and slice them into bite-sized pieces.
Mix the miso sauce (miso, gochujang, minced garlic, sesame oil, and a bit of water) and prepare it.
Top the rice with the vegetables and tuna.
Add the prepared miso sauce on top.
Finish by sprinkling sesame oil and roasted sesame seeds, then mix well to serve.