Ingredients

HERBED MAYONNAISE

1. 1 cup mayonnaise
2. 1 tablespoon coarsely chopped tarragon
3. 1 tablespoon coarsely chopped flat-leaf parsley
4. 1 tablespoon coarsely chopped chives

COD CAKES

1. 1 pound skinless salt cod fillet
2. 3 cups milk
3. 2 cups diced (1-inch) peeled Idaho potatoes (about 3 medium)
4. 2 tablespoons olive oil
5. 1 cup thinly sliced scallions (about 1 bunch)
6. 1/3 cup heavy cream
7. 2 tablespoons coarsely chopped tarragon
8. 1 tablespoon coarsely chopped flat-leaf parsley
9. Salt and freshly ground pepper
10. All-purpose flour, for dusting
11. Vegetable oil, for frying

Directions

1. make the herbed mayonnaise: Combine all of the ingredients in a medium bowl and refrigerate.
2. make the cod cakes: In another bowl, cover the salt cod with water and soak overnight in the refrigerator, changing the water once or twice. Drain and rinse the fish and transfer to a large saucepan. Add the milk and simmer over moderate heat until the cod flakes easily, about 10 minutes. Drain the cod and discard the milk. Coarsely flake the fish and transfer it to a large bowl. 
3. Meanwhile, in a medium saucepan, cover the potatoes with water. Bring to a boil and cook until just tender, about 10 minutes. Drain well and let cool slightly. Using your hands, mix the potatoes with the cod; the mixture should be chunky. 
4. Heat the olive oil in a medium skillet. Add the scallions and cook over moderately low heat until tender, about 4 minutes. Add the scallions to the cod mixture along with the cream, tarragon and parsley. Season with salt and pepper. Shape the mixture into 3-inch cakes, about 3/4 inch thick. Lightly flour the cakes and set them on a baking sheet. 
5. Heat 1/2 inch of vegetable oil in a large skillet. Working in batches, fry the cod cakes, turning once, until golden brown and crisp, 3 to 4 minutes. Drain on paper towels and keep warm while you cook the remaining cakes. Serve with the herbed mayonnaise.
   

Make Ahead

The mayonnaise and the fried cod cakes can be refrigerated for up to 2 days. Rewarm the cod cakes in a 325° oven.