Line a rimmed sheet pan with heat-resistant parchment paper.
Shred the cheese and the onion using the medium shredding blade of a food processor or the large hole side of a hand grater (there’s no need to rinse the grater between the cheese and the onion).
Toss the cheese and onions well, then spread out in an even layer on the prepared pan.
Drizzle generously with olive oil and sprinkle with the salt and garlic powder.
Bake for 20 minutes or until the onions and cheese have browned.
It will be bubbly when you take it out of the oven.
Allow to cool to room temperature to crisp up, about 20 minutes.
Then cut into thirds for sandwich wraps and fill as desired.