Combine everything from the tuna mixture and set aside until ready to use
Take each slice of bread and spread a 1/2 TBSP of light mayo on each side then sprinkle some garlic powder on top.
Place the bread, mayonnaise side down onto a low heat pan
Split the tuna mixture into two portions
Add the tuna mixture, one slice of cheese following with the other slice of bread (mayonnaise side up)
Brown on both sides and enjoy