Ingredients
Equipment
Method
Prepare the gratin
- Heat the oven to 400°F.
- Grease a 9x13-inch baking dish with 1 teaspoon of the olive oil.
- Arrange the cod, shrimp, and scallops in an even layer in the prepared dish.
Make the sauce
- Melt the butter in a medium saucepan over medium heat.
- Add the shallot and cook for 3 minutes until softened.
- Stir in the flour and cook for 1 minute, stirring constantly.
- Gradually whisk in the wine, then the milk and cream.
- Bring the sauce to a gentle simmer and cook for 4 to 6 minutes, whisking, until thick enough to coat the back of a spoon.
- Stir in the Dijon, salt, pepper, and nutmeg.
Add the topping and bake
- Pour the hot sauce evenly over the seafood.
- Bake for 12 to 15 minutes at 400°F.
- Toss the panko and Parmesan with the remaining 1 tablespoon olive oil.
- Scatter the panko mixture evenly over the gratin.
- Bake for 8 to 12 minutes more at 400°F, until the topping is golden and the thickest cod pieces reach 145°F; the shrimp and scallops should be opaque.
- Rest the gratin for 5 minutes before serving.
Notes
Pat the scallops dry so the sauce stays creamy rather than watery. Refrigerate leftovers for up to 3 days; freezing is not recommended because the cream sauce may separate. For a gluten-free version, use gluten-free flour and panko.
