1. Preheat panini press grill (I used a George Foreman).
2. Mix together the tuna, yellow onion, lite mayo and salt & pepper to taste.
3. Place the provolone cheese on a piece of gluten-free bread and then add the tuna mixture and the other piece of bread on top.
4. Grill in the panini press for 4-5 minutes until hot and toasty - enjoy!
