Dice the beef. Clean and dice the peppers. Peel onion and dice. Scramble the egg.
Preheat wok, add oil and turn up heat to medium hot. Add eggs and fry until solid, then transfer to a plate. Add beef, onion, peppers and stir fry. Add salt, soy sauce and stir well. Add fried eggs and cold rice, then stir fry. When rice becomes hot it is ready to be served.