Answer:
Iron roof, glass walls, burns and burns and never falls.
I never was, am always to be. No one ever saw me, nor ever will. And yet I am the confidence of all, To live and breath on this terrestrial ball.
Iron on a mammal. Mammal on your feet.
What goes through the door without pinching itself? What sits on the stove without burning itself? What sits on the table and is not ashamed?
Some live in me, some live on. And some shave me to stride upon. I rarely leave my native land. Until my death I always stand. High and low I may be found. Both above and below ground.
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.