In a large bowl, combine the cooked rice, sesame oil, soy sauce, and salt. Mix well until the rice is evenly coated.
Add the black and white sesame seeds, green onions, chopped protein, and vegetables to the rice mixture. Stir until all ingredients are well incorporated.
Wet your hands with water to prevent sticking. Take a small handful of the rice mixture and shape it into a ball or triangle, about the size of a golf ball. Repeat until all the mixture is shaped.
If desired, wrap each rice ball with a strip of nori for added flavor and presentation.
Serve immediately or refrigerate for up to 2 hours before serving. Enjoy as a snack or light meal.