Pour boiling water over the tomatoes, remove the skin and cut into medium-sized cubes.
Bring the broth to a boil, add pepper and soy sauce – in principle, salt may not be needed, soy sauce gives “salinity”. Add the tomatoes and bring to a boil again.
Beat the egg until smooth in a separate bowl.
When the tomatoes boil, mash the soup with a spoon and slowly pour in the egg, stirring constantly.
Serve immediately, sprinkled with green onions.
Very fast, simple and delicious.