1/4 cup evaporated milk
1/2 teaspoon sugar
1/2 teaspoon active dry yeast
1 large egg, beaten
1 tablespoon melted unsalted butter
1 3/4 cups cake flour
2 tablespoons minced chives
1 teaspoon finely grated lemon peel
1/2 teaspoon salt
1/2 teaspoon fennel seeds, crushed
1/8 teaspoon each, black pepper and cayenne pepper
Light olive oil and/or vegetable oil, for frying
For the fish: If using salt cod, in a large pot, cover cod with the 8 cups water, cover pot and let stand overnight. If using smoked fish, skip this step.
Drain cod, rinse well, drain again. Transfer to a medium saucepan over medium heat. (Or place smoked whitefish in pan.) Add whole milk, garlic and bay leaf. Bring to a simmer, reduce heat to low and poach fish for 20 minutes. Drain, reserving poaching liquid. Discard bay leaf. Place cod and garlic on a plate and use a fork to finely mash them together. If using whitefish, remove skin and any bones first, then mash fish together with garlic. Set aside.
In a small skillet, heat the olive oil and sauté onion in it for about 5 minutes, until translucent. Set aside.
For the batter: in a small saucepan, heat 1/2 cup of the fish poaching liquid, the evaporated milk and sugar to 105 degrees. Transfer to a medium bowl. Sprinkle yeast over top. Let stand 15 minutes, until "spongy." Stir in beaten egg and melted butter.
In a large bowl, whisk together the cake flour, minced chives, lemon peel, salt, fennel seed and black and cayenne peppers. Stir in yeast mixture. Stir in cod/fish mixture, then onion. Stir 1 minute longer.
Butter (or use shortening) a medium bowl. Transfer batter to bowl, cover with plastic wrap and let stand at room temperature for 1 hour. Or refrigerate, then bring to room temperature 1 hour before frying.
To finish: Heat oven to 300 degrees. Line a baking sheet with paper towels.