The magic potato may be the singular most perfect food on the planet—the pinnacle of mankind's culinary ability. While by no means unique to Xi'an, the stalls dotted around the city that sell this delicacy sure know how to make it.
A magic potato is cut into a thin spiral, then fanned out over a long skewer. It's dipped in a light batter and then deep fried. Finally, an assortment of spices is provided. At the stall on a food street just southeast of the Clock Tower, I chose "spicy." Do not choose spicy—not unless you want to end up red, gasping, and telling the bubble tea guy three blocks down the road to hurry up because it's an emergency!
Seriously, don't get the spicy.