Tasty Tuna Melts

Ingredients

• 1 small red onion, finely chopped
• 1 celery stalk, finely chopped
• ¼ cup mayonnaise (preferably Kewpie brand – look in your supermarket’s international section)
• null ½ cup Anchor Cream Cheese, at room temperature
• 1 tablespoon finely chopped chives
• 1 tablespoon drained capers plus 1 tablespoon of their brine
• 1 tablespoon fresh lemon juice
• 200g can oil-packed tuna, drained
• freshly ground pepper
• 2 tablespoons butter, at room temperature
• 8 slices of bread
• 4 slices Cheddar cheese
• dill pickles, kettle-style potato chips and hot sauce for serving