Answer:
I can travel from there to here by disappearing, and here to there by reappearing.
Lighter than what I am made of, More of me is hidden Than is seen.
What is so fragile that saying its name breaks it?
What flies forever, Rests never?
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.