Answer:
What can you catch but not throw?
A hole in a pole, though I fill a hole in white. I'm used more by the day, and less by the night.
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
A box without hinges, lock or key, yet golden treasure lies within.
Brown I am and much admired; many horses have I tried; tire a horse and worry a man; tell me this riddle if you can.
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.