Answer:
A hill full, a hole full; yet you cannot catch a bowl full. What is it?
I tremble at each breath of air, and yet can heaviest burdens bear.
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.
White bird, featherless, flying out of paradise. Flying over sea and land. Dying in my hand.
What surrounds the world, yet dwells within a thimble?
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.