Put the rice in a bowl.
Julienne the assorted vegetables (carrot, cucumber, spinach, etc.).
Drain the oil from the tuna using a strainer and prepare it.
Place the vegetables and tuna on top of the rice.
Make the sauce with gochujang (Korean chili paste), soy sauce, sesame oil, sugar, and vinegar.
Pour the sauce on top.
Add toppings (egg, dried seaweed flakes, etc.) and mix well before eating.