Place tuna, burger sauce, pickles, pickling liquid, lemon juice and shallot in a bowl. Stir to combine.
Place half the garlic bread slices on a board, buttered-side down. Top with extra burger sauce, tuna mixture, mozzarella and remaining garlic bread slices, buttered-side up.
Place, in batches, in the basket of an air fryer. Cook at 200C for 7-8 minutes or until golden. Serve.
