Butter your bread like you would for making grilled cheese.  Slice cheese to cover one bread slice.  Set aside.

Crack egg into cup or small bowl and beat with a fork.  Add any spices you like, (my favourites are Cajun, sage, Italian, black pepper).  Fry in your pan.  When egg is done, set on top of cheese and put lid on sandwich.  Then place in frying pan and fry until bread is browned.

This is just a twist on a regular grilled cheese, but is quick and easy and good for handing to someone who has to run out the door but very filling.   Also, you can add a slice of ham or several strips of bacon.