Salt Cod Potato Gratin
The secret to making this Portuguese-inspired gratin is to soak the salt cod in water for 24 hours to remove the salt and rehydrate the fish. Here we mix the cod with tender Yukon Gold potatoes and half-and-half, then sprinkle with Parmesan and bake until golden brown. Spread the warm gratin on slices of crusty baguette and serve with other small plates, know as pesticos in Portugal. Pour a crisp white Vinho Verde alongside and enjoy.
- 1 lb. (500 g) salt cod
- 6 garlic cloves, peeled and smashed
- 1 bay leaf
- 3 fresh thyme sprigs
- 1 lb. (500 g) Yukon Gold potatoes, peeled and quartered
- Kosher salt and freshly ground black pepper
- 3/4 cup (6 fl. oz./180 ml) half-and-half
- Grated zest and juice of 1 lemon
- 1/4 tsp. cayenne pepper
- 2 Tbs. grated Parmesan cheese
- Chopped fresh flat-leaf parsley for garnish
- Baguette slices for serving
Rinse the salt cod, place in a bowl and cover with cold water. Cover the bowl and refrigerate for 24 hours, changing the water 4 times, then drain.
Place the salt cod in a large saucepan and cover with cold water. Add the garlic, bay leaf and thyme. Set over medium-high heat and bring to a simmer. Reduce the heat to medium-low and cook until the cod is flaky, about 10 minutes. Remove from the heat and let the cod stand in the cooking liquid for 20 minutes.
Meanwhile, place the potatoes in a pot of salted cold water. Set over medium-high heat and bring to a boil. Reduce the heat to medium-low and cook until the potatoes are very tender, about 20 minutes. Drain and set aside.
Position a rack in the upper third of an oven and preheat to 400°F (200°C). Grease a 2-quart (2-l) gratin dish or shallow baking dish.
Drain the salt cod, reserving the garlic; discard the bay leaf and thyme. Transfer the cod and garlic to the bowl of an electric mixer fitted with the flat beater and beat on medium speed until smooth, about 5 minutes. With the mixer running, slowly add the half-and-half and beat until the mixture is smooth and creamy, about 1 minute. Stop the mixer and scrape down the sides of the bowl. Add the potatoes, lemon zest, lemon juice, cayenne and black pepper to taste. Beat on medium speed until the potatoes are blended in and the mixture is smooth and creamy, 1 to 2 minutes. Season to taste with salt and black pepper.
Transfer the salt cod–potato mixture to the prepared gratin dish and sprinkle with the Parmesan. Bake until the top is golden brown, 20 to 25 minutes. Garnish the gratin with parsley and serve with baguette slices. Serves 6 to 8.
Note: If you can’t find salt cod, substitute 1 lb. (500 g) fresh cod fillets. Place in a baking dish, cover with 1/2 cup (4 oz./125 g) kosher salt in an even layer and refrigerate for 1 hour. Rinse the fish, then place in a bowl and cover with cold water. Cover the bowl and refrigerate for 30 minutes, changing the water twice.
Williams Sonoma Test Kitchen