Italian Sweet-Pickled Fish

I first made this classic Neapolitan dish back in 1989 at a restaurant I worked in called Friths in London’s Soho, which chef Carla Tomasi owned. I tend to make this dish with whole anchovies or baby mackerel or sardines, bat red mallet, gurnard, tarakihi and snapper fillets work well too. Use either six fillets from three large fish, or 12 smaller filets from six fish. Scale the fish bat keep the skin on and remove the bones from the larger fish. I serve it as a starter, on toasted sourdou