Two days before serving, soak the cod in 1 quart of milk in a covered bowl in the refrigerator for 24 hours. The next day, discard the milk and rinse the cod well with cold water. Put the cod in a fresh quart of milk and refrigerate for another 24 hours. Discard the milk and rinse well with cold water. Pat dry and flake into small pieces.
In a large saucepan, combine the onions, celery, potatoes, 2 teaspoons of the garlic, and the water. Season with salt and pepper. Bring to a boil, then reduce the heat to medium and cook until the potatoes are fork tender. Drain and put the mixture into a large mixing bowl. Add the cod, 1 tablespoon of the parsley, the remaining tablespoon garlic, the olive oil, 1 of the eggs, and the heavy cream. With a potato masher, mash and mix until thoroughly blended. Season with salt and pepper. Let cool completely.
Divide the mixture into 2 equal portions. Place each portion in the center of 2 large pieces of plastic wrap. Wrap the mixture in the plastic wrap and form into logs, each about 1 inch in diameter and 12 inches long. Unwrap, then cut the log crosswise into 2-inch lengths. Put the flour in a small mixing bowl and season with Essence. In another small mixing bowl, whisk the remaining 2 eggs and 2 tablespoons milk together. Season with salt and pepper. In a third small mixing bowl, put the bread crumbs and season with Essence.
Heat 4 inches of oil in a large, heavy pot or electric fryer to 360?F. Dredge each cake in the seasoned flour, coating completely and tapping off any excess. Dip the cake in the egg wash, letting the excess drip off, then dredge in the seasoned bread crumbs, coating each side completely.
Fry the cakes several at a time without crowding in the hot oil until golden brown, 3 to 4 minutes, turning them around to brown evenly. Drain on paper towels. Season with Essence.
Serve warm with the tartar sauce and garnish with the remaining 2 tablespoons parsley.
Yields: 4 appetizer servings