Begin by draining a can of tuna and transferring it to a medium mixing bowl. Use a fork to break up the tuna into smaller flakes.

Chop half an onion, one celery stalk, and a handful of parsley, then mince a clove of garlic. Add these to the tuna bowl.

Add a few tablespoons of mayonnaise and a drizzle of extra virgin olive oil, then mix until well combined. Season with salt and pepper to taste.

Heat a non-stick skillet over medium heat and add softened butter and a splash of olive oil to coat the bottom.

Place a slice of bread in the skillet, add the tuna mixture generously, then top with another slice of bread, butter-side down.

Grill for about 3-4 minutes until the bottom slice turns golden brown. Flip the sandwich and grill the other side until crispy and cheese melts.

Remove from the skillet, let it rest for a minute, then slice in half and serve warm.