Preheat the oven to 200 degrees F.
Heat 3 tablespoons of the butter in a large (12-inch) saute pan over medium-high heat. Add the onion, celery and bell pepper and cook over medium heat for 8 to 10 minutes, stirring occasionally, until tender. Place the fish on top of the vegetables and add the cream, 1 teaspoon salt and 1/2 teaspoon black pepper. Bring to a boil, lower the heat, cover and simmer for 6 to 12 minutes (depending on the thickness of the cod), until the fish is just cooked. Set aside in the pan for 10 minutes, then flake the fish into large pieces with a fork.
Put 2 cups of the panko in a large bowl. Add the cod mixture, including the cooking liquid, the dill, mayonnaise, mustard, lemon zest, eggs, lobster, 2 teaspoons salt and 1 teaspoon black pepper and mix gently.
Using a 2 1/4-inch ice cream scoop as a measure, shape the mixture into 14 (3-inch) fish cakes. Place the remaining 2 cups of panko on a plate and coat the cakes all over, patting the coating to adhere. Wipe the saute pan clean with a paper towel and heat 2 tablespoons of the butter and 2 tablespoons of oil in the pan over medium heat. Place 5 cakes in the pan and cook for 5 minutes on each side, until nicely browned on both sides. Transfer the cakes to a sheet pan and keep them warm in the oven for up to 15 minutes. Repeat, adding more butter and oil, until the entire mixture is cooked. Serve hot with the remoulade sauce.
Remoulade Sauce: Place the mayonnaise, cornichons, mustard, vinegar, 1 1/2 teaspoons salt and 3/4 teaspoon pepper in the bowl of a food processor fitted with the steel blade. Pulse a few times until the cornichons are finely chopped (not pureed). Transfer to a sealed container and refrigerate for up to 5 days.
Photograph by Steve Giralt
If you prefer to cook the lobsters yourself, two 1 1/2-pound lobsters will yield 1/2 pound of cooked lobster meat.
Recipe from Cooking For Jeffrey: A Barefoot Contessa Cookbook. Copyright © 2016 by Ina Garten. By arrangement with Clarkson Potter/Publishers, A Division of Random House, LLC.