Answer:
Stealthy as a shadow in the dead of night, cunning but affectionate if given a bite. Never owned but often loved. At my sport considered cruel, but that's because you never know me at all.
You can always see it, but it's too far away to touch. Mountains rest on it, and at sea it surrounds you. What is it?
They belong to me; they belong to you; They can make you feel happy or make you feel blue; They never end until the day you do.
The more of them you take, the more you leave behind. What are they?
I can move even when you are still. I can be one or many.
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.