Cut chicken breast and tomato into small pieces.
Finely chop onion and green onion.
Heat cooking oil in a pan and stir-fry onion and green onion.
Add chicken breast and cook until done.
Add tomato and stir-fry together.
Add rice and stir-fry until all ingredients are well mixed.
Season with salt, pepper, and soy sauce.
Serve in a bowl and enjoy.