In a pan, heat vegetable oil over medium heat.
Add the beef (or tofu) and cook until browned and fully cooked.
Season with a bit of soy sauce and salt to taste. Remove from heat and set aside.
Sauté the carrots in a bit of oil until tender. Season with salt.
Blanch the spinach in boiling water for about 1 minute, then rinse with cold water. Squeeze out excess water and season with a bit of sesame oil and salt.
Slice the cucumber into thin strips.
In a bowl, beat the eggs and season with a pinch of salt.
Heat a non-stick pan over medium heat and make a thin omelet. Cook both sides until fully set. Remove and slice into thin strips.
In a large bowl, mix the cooked rice with sesame oil and a pinch of salt.
Place a sheet of seaweed on a bamboo sushi mat, shiny side down.
Spread a thin layer of rice over the seaweed, leaving a 1-inch border at the top edge.
Arrange the beef (or tofu), carrots, cucumber, pickled radish, spinach, and egg strips in a line across the rice, closer to the bottom edge.
Using the bamboo mat, gently roll the seaweed over the fillings, pressing firmly to shape the roll. Seal the edge with a bit of water.
Using a sharp knife, slice the roll into bite-sized pieces. Wipe the knife with a damp cloth between cuts to keep it from sticking.
Garnish with sesame seeds.
Enjoy your meal!