NOTE: USE 20-QT STOCK POT AND SET SERVINGS TO 20. WILL MAKE 19 QT JARS.

In a large pot, heat the oil over medium-high heat. Add the onions, celery, garlic and fennel, and cook, stirring, until soft (about 4 minutes for 8 servings and 10 for 16 servings). Add the bay leaf, salt, oregano, red pepper, fennel seeds, thyme, cayenne pepper, and black pepper, and cook, stirring, until fragrant, about 2-3 minutes. Add the tomato paste and cook until starting to brown, about 2-4 minutes. Add the white wine, stir to deglaze the pan, and cook until the wine evaporates to the consistency of a ragu (about 5-10 minutes).

Add the plum tomatoes and their juices and the fish or chicken stock and bring to a boil. Reduce the heat and simmer, partially covered, for 30 minutes.

Lightly season the fish, crab, scallops, shrimp and clams with the Essence, and add to the pot 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.