Prepare the vegetables into a small dice ready for a quick cook and the meat into thin slices if using.
Heat oil in a pan until hot.
Add the meat, cook until half done or so.
Add the vegetables and stir fry for a few minutes.
If scrambling the egg, push the meat and vegetables to one side of your pan. Add the egg in the empty area (might need a touch more oil here), and scramble so as to have distinct pieces of egg opposed to it just coating the meat and vegetables.
Add the rice and continue to stir fry.
Season with soy sauce to your particular taste and it really is as simple as that.