Begin by rinsing the short-grain rice under cold water until the water runs clear. Cook the rice according to package instructions for about 20 minutes, then allow it to cool for 10 minutes.

In a large mixing bowl, combine the warm rice with sesame oil and a pinch of salt. Gently fold in carrots and spinach until evenly mixed.

In another bowl, blend together diced pickled radish with either seasoned ground beef or crumbled tofu until well-combined.

Lightly wet your hands, take a handful of the rice mixture, flatten it, and place a tablespoon of filling in the center. Shape it into a smooth ball.

Cut nori sheets into strips and wrap each rice ball snugly, securing them for freshness.

Arrange the rice balls on a platter and serve warm or at room temperature, optionally with dipping sauce.