Sgombri avec le cipolle

Sgombri con le cipolle is a traditional dish originating from eastern Liguria. It's usually made with a combination of mackerel fillets, sliced onions, white wine and white wine vinegar, thyme, bay leaves, juniper berries, salt, and pepper. The fish is layered in an ovenproof dish with the sliced onions, wine, vinegar, salt, pepper, and juniper berries. The dish is baked, then left to cool and chilled for a day. A few hours before serving, sgombri con le cipolle is taken out of the fridge and brought back to room temperature before it's enjoyed.