1. thoroughly drain can by removing the lid and then pressing it down onto the tuna over the sink.
  2. mix tuna in a bowl with mayonnaise, relish, red onion, and sriracha.
  3. make a sandwich with the tuna mixture and a slice of cheese.
  4. melt 1/2 tbsp of butter in a pan on medium-low heat.
  5. place the sandwich in the pan over the butter.
  6. cook for about 3 minutes or until the bottom of the bread is well toasted.
  7. remove sandwich from the pan, melt another 1/2 tbsp, and replace flipped sandwich.