Directions

1. Soak the dried salted cod in cold water with the skin side up for 24 hours, changing the water about 4 times. Drain and discard the water.
2. Preheat an oven to 350 degrees F (175 degrees C).
3. Place the cod in a pan with enough water to cover; bring to a boil and cook for 10 minutes. Remove the cod from the pan; remove and discard the skin and bones. Cut the cod into chunks and set aside.
4. Heat 2 tablespoons olive oil in a skillet; cook the potatoes in the hot oil until just cooked, about 5 minutes. Transfer to a plate lined with paper towels to drain.
5. Pour 2 tablespoons more olive oil to the skillet; cook the onion and garlic in the skillet until the onion is translucent, about 5 minutes. Add the cod and cook another 3 minutes; stir the potatoes into the mixture and cook another 1 to 2 minutes. Reduce heat to low.
6. Melt the butter in a separate skillet over medium-low heat; vigorously stir the flour into the melted butter. Slowly stream the hot milk into the mixture while stirring; cook and stir until thick. Season with the nutmeg. Pour into the skillet with 1 1/3 cups heavy cream; stir to coat. Allow the mixture to simmer together for about 2 minutes. Season with salt and pepper; transfer to a small baking dish. Drizzle another 2/3 cup heavy cream over the mixture; sprinkle with the Parmesan cheese.
7. Bake in the preheated oven until the top is browned, 30 to 40 minutes. Serve hot.