Brodetto

Instructions

1. In a heavy 6- to 8- quart pot, bring the vinegar to a lively bubble. Add the onions, turn the heat to low and partially cover the pot. Cook for 15 minutes, or until the onions are soft and almost transparent. Stir occasionally. If the liquid threatens to evaporate, add about ¼ cup water. Once the onions are soft, uncover the pot and let the vinegar bubble gently, stirring frequently, until it evaporates. 
2. Add the oil, a little salt, and a generous sprinkling of freshly ground black pepper. Slowly sauté over medium low-heat, uncovered, or until the onions turn golden.
3. With the heat still at medium-low, stir in the lemon zest and garlic, and cook about 1 minute.  Add the tomatoes, raise the heat to high and boil, uncovered 5 minutes or until thick.
4. Pour in the wine and bring the mixture to a boil. Boil over high heat 5 minutes, or until the mixture is reduced by about one third and no raw alcohol taste is left from the wine. Taste for seasoning.
5. If you are using squid, cook it at a very gentle bubble about 20 minutes or until tender, before adding the remaining seafood. Layer the firm-fleshed fish in the pot, topping it with the thinner, flakier fillets. Scatter the shrimps and clams on top of the fish. Using the back of a wooden spatula, gently press the fish into the sauce. Bring the liquid to a slow bubble. Cover and cook 5 to 10 minutes or until the thickest pieces are firm and opaque to their centers. 
6. Ladle the Brodetto into soup plates or bowls.