In a large pot, heat the oil over medium-high heat. Add the onions, bell peppers, and celery, and fennel , and cook, stirring, until soft, about 4 minutes. Add the garlic, bay leaf , salt, oregano, red pepper, fennel seeds, thyme, and black pepper, and cook, stirring, until fragrant, about 1 minute. Add the tomato paste and cook until starting to brown, about 2 minutes. Add the white wine, stir to deglaze the pan, and cook until half of the wine is evaporated, about 2 minutes. Add the plum tomatoes and their juices and the fish stock and bring to a boil . Reduce the heat and simmer, partially covered, for 30 minutes. Add the crab quarters, clams, and mussels, and simmer until the shells open, about 6 to 7 minutes. Remove and discard any unopened shells. Lightly season the fish and shrimp with the Essence, and add to the pot. Add the oysters, and stir. Simmer, covered, until cooked through, about 5 minutes. Remove from the heat and discard the bay leaf. Stir in the parsley . Ladle into large soup bowls and sprinkle each serving with Parmesan cheese and green onions. Serve immediately with hot bread. 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.