Answer:
Thirty white horses on a red hill, first they champ, then they stamp, then they stand still.
What an fill a room but takes up no space?
The more of them you take, the more you leave behind. What are they?
What flies forever, Rests never?
Put into a pit, locked beneath a grate, guarded through the night, yet it still goes out.
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.