Place the salmon, skin side down, on the rack of a fish poacher. (Alternatively, place the salmon on a large piece of cheesecloth that will fit inside a large heavy roasting pan that can be placed over 2 burners on the stove.) Lightly season the fish with Essence.
To make the poaching liquid, to the fish poacher add the bay leaves, lemon slices, peppercorns, garlic, onions, carrots, parsley stems and thyme to the pan. Pour in the Champagne and add enough water as will be necessary to cover the fish. Bring to a boil. Reduce the heat and simmer for 15 to 20 minutes.
Very carefully, lower the fish into the poaching liquid and return to a bare simmer. Cover and simmer until the fish is tender and cooked through, 10 to 15 minutes.
Very carefully, lift the fish from the poaching liquid. Using 2 large slotted spatulas, lift the fish from the rack and place on a baking sheet or tray to cool. When cool, gently peel away the skin, leaving the fish whole. Serve warm, or cover and chill slightly in the refrigerator, if desired. (Salmon can be cooked 1 day in advance.)
To serve, line a large platter with baby spinach leaves and top with the salmon. Arrange the langoustines around the fish. Top the fish with the anchovy dressing, garnish with chopped parsley, and serve.
Combine all ingredients thoroughly and store in an airtight jar or container.
Yield: about 2/3 cup
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch. Published by William and Morrow, 1993.