Preserved lemons are salted lemons cut a vertical cross in each lemon and stuff with sea salt preserve in lemon juice for a few weeks in an air-tight jar. If you don't have them use ordinary lemons. The advantage of the preserved ones is their mildness and tenderness, so you can eat them. The unpreserved ones tend to be too bitter. If you don't have fish stock use 3 oz each white wine and water. Method: Brown the fish in olive oil using the casserole you will use for the roasting. Season with salt and pepper and set aside. Peel and trim the carrots and cut lengthways into thin strips. Top and tail the beans and roughly chop the black olives. In the same pan lightly colour the vegetables in hot oil. Add the black olives and preserved lemon, cut into eight segments, and toss in the oil. Pour over the stock, bring to the boil, lower the heat, lay the fish on top and cover with the lid, and tinfoil if using. Cook over a moderate heat for eight minutes, basting the fish twice during the process. Remove the fish and keep warm. Continue cooking and vegetables with the lid off until tender. Serve with the fish on top and sprinkling of parsley.