The word fajita originally referred to a particular cut of beef. It was tough and benefited from marinating before cooking.
The fame and popularity of fajitas spread like wild fire across the United States and across the world making it today the most popular Mexican dish on any menu.
Beef or Chicken,
Cheddar cheese or whichever cheese you prefer,
Cut up meat and season with the fajita seasoning.
Let it sit for about 1 hour preferably overnight.
Put some olive oil in skillet and stir fry the meat till done.
Take out the meat and add the cut up vegetables.
Put the meat back in the pot and put you fajita together.