There’s something undeniably comforting about a creamy, bubbling casserole pulled straight from the oven, and this Seafood Chowder Casserole might be the coziest! Inspired by classic East Coast seafood chowder but reimagined as a baked dish, it features thin-sliced potatoes, a rich cheesy sauce, and a mix of seafood: salmon, cod, crab, scallops, and a hint of smoked salmon for depth.
This post may contain affiliate links. Read my disclosure policy.
Whether you're planning a special family dinner, hosting guests for a cozy gathering, or simply craving something indulgent and warming, this seafood casserole recipe definitely delivers it. It's hearty enough for a main course, yet refined enough to impress, especially when paired with a light salad or a side of roasted vegetables. And the best part? It’s easy to make ahead. Simply assemble the casserole, cover it, and refrigerate until you're ready to bake. It's perfect for busy weekends, holiday dinners, or even prepping a few days in advance for a crowd.
Recipe Overview
⏱️ Ready in: 1 hour 10 minutes (including prep and bake time)
🍽️ Servings: 6–8
💪 Diet-Friendly: High-Protein, Pescatarian
Jump to:
Why You’ll Love This Seafood Casserole
- It's flavorful and rich: Like my Simple Seafood Soup and the Salmon Stuffed With Shrimp dish, this casserole is full of tender fish and creamy goodness!
- Make-ahead friendly: It's a great option for holidays or Sunday meal prep.
- Thin-sliced potatoes: They soak up the creamy juices and cook until tender!
Ingredients
- Salmon: Rich and buttery! We'll be using skinless salmon and cutting it into bite-sized cubes. Use wild-caught if possible.
- Cod or Halibut: Also cut into bite-size cubes. It's flaky and mild, which is a great contrast to the salmon.
- Crab meat: Adds a little bit of sweetness. Use lump crab for luxury, or imitation crab (like we do in these Chickpea and Crab Salad and Sautéed Seafood Medley recipes) for a budget-friendly option.
- Bay scallops: I like using Bay scallops because they are small and sweet, but if you're using large sea scallops, cut them into smaller pieces.
- Smoked salmon: Adds smoky, savory depth. A little goes a long way for that smoky, savory kick.
- Potatoes: Yukon gold works best. We'll be thinly slicing them, preferably with a mandoline to avoid pre-cooking.
- Cheese: white cheddar or mozzarella both melt great.
- Breadcrumbs and Butter: Panko adds a nice crunch, but regular breadcrumbs work too. We'll be mixing the breadcrumbs with butter to help with browning.
See the recipe card below for the full ingredient list and quantities.
Substitutions and Variations
- Crab: Swap with more cod, scallops, or even canned clams (drained).
- Scallops: You can use shrimp, extra white fish, or simply leave them out.
- Cod or Halibut: Haddock, pollock, or even tilapia make great substitutes. Just go for a firm, mild white fish.
- Smoked Salmon: If you don’t have smoked salmon, add a sprinkle of some cooked bacon bits for smoky flavor. I use them in this Easy Cottage Cheese Wraps recipe, and it adds the perfect amount of smoke to the flavors.
- Cheese: Try a mix of Gruyère and Parmesan for a bolder, nutty flavor, or go mild with Monterey Jack. Smoked cheddar also works great.
- Breadcrumbs: Crushed Ritz crackers or even crushed potato chips all make great crunchy toppings.
- Make it Dairy-Free: Use vegan butter and unsweetened oat or almond milk. For cream, try full-fat coconut milk - it works great with cod like in this Baked Cod with Mushroom Sauce in Parchment Paper.
- Gluten-Free Version: Use gluten-free flour for the roux and swap in gluten-free breadcrumbs or crushed GF crackers for the topping.
- Add More Veggies: Fold in frozen peas, corn, or chopped spinach. Sautéed mushrooms, leeks, or carrots can also be added when cooking the onions.
- Spice It Up: Add ¼ to ½ teaspoon of cayenne to the sauce, or mix in a pinch of chili flakes for subtle heat.
Step-by-Step Instructions
STEP 1: Preheat your oven to 375°F (190°C) and lightly grease a 9"x13" casserole dish with butter or oil, and set aside.
STEP 2: Prep the Potatoes
Thinly slice the Yukon Gold potatoes using a mandoline (about ⅛-inch thick). Arrange half of the potato slices on the bottom of a greased 9"x13" casserole dish. Season with a pinch of salt and pepper and set aside.
STEP 3: Make the Creamy Sauce
Sauté onion and garlic in butter, then stir in flour to make a roux. Slowly whisk in milk, stock, and cream. Once thickened, stir in shredded cheese, salt, pepper, and Old Bay seasoning. Simmer gently, then remove from heat.
STEP 4: Add the Seafood
Fold the salmon, cod, crab, scallops, and smoked salmon into the sauce mixture.
STEP 5: Assemble the Casserole
Spoon half of the seafood mixture evenly over the bottom half of the potatoes. Top with the remaining potato slices. Season again lightly with salt and pepper, and spread the remaining seafood mixture over the top layer of potatoes. Sprinkle shredded cheese over the top.
STEP 5: Make the Breadcrumb Topping
In a small bowl, combine the breadcrumbs and melted butter and mix well until the breadcrumbs are coated, then add the buttered breadcrumb mixture on top of the cheese layer.
STEP 6: Top and Bake
Cover loosely with foil and bake for 30 minutes. Remove the foil and bake for another 20-25 minutes, until bubbling and golden. Remove from oven and let the casserole rest for 5–10 minutes before serving.
Top Tips for the Best Seafood Chowder Casserole
- Slice the potatoes thin and evenly. A mandoline is the best for this! It ensures the potatoes cook through without needing to be parboiled.
- Don’t overcook the sauce. Once it thickens and the cheese is melted, remove it from the heat. Overcooking can cause it to separate.
- Taste the sauce before assembling. Adjust salt, pepper, or seasoning before mixing in the seafood. It’s just easier to balance now than later.
- Make sure to layer potatoes twice! This ensures that every bite has the seafood and potatoes.
Frequently Asked Questions
Yes, you can. Just make sure to thaw it completely in the fridge overnight and pat it dry with paper towels before adding it to the sauce. This helps prevent excess water from thinning out your creamy base and ensures that the seafood bakes evenly and doesn't turn rubbery. If you're using pre-cooked frozen seafood, you can still add it directly, but make sure to stir it in at the end of the sauce step so it warms gently and doesn’t overcook in the oven.
Yes, you can definitely freeze the casserole before baking it. Assemble it without the breadcrumb topping, let it cool, then wrap it tightly and freeze for up to 2 months. Thaw overnight in the fridge, add the topping, and bake as usual. Avoid freezing the casserole after baking it, since the cream sauce may separate and the seafood can become rubbery.
You can assemble the entire casserole up to 24 hours in advance (minus the breadcrumb topping). Cover it and refrigerate. When ready to bake, add the breadcrumb topping and pop it in the oven. This keeps the topping crispy and golden. For extra texture, broil at the end, but keep a close eye on it so it doesn't burn.
What to Serve with the Casserole
This creamy seafood casserole is rich and hearty on its own, so lighter sides work best to balance it out. A mixed green salad, such as this Spring Vegetable and Berry Salad, or some roasted vegetables such as these Air Fryer Roasted Vegetables with Sweet Potatoes & Shallots, or these Healthy Turmeric Oven Roasted Vegetables. Or, just serve it with some crusty bread or garlic toast to soak up the creamy sauce.
Other cozy recipes
If you tried this Creamy Seafood Chowder Casserole recipe or any other recipe on my website, please leave a 🌟 star rating and let me know how it went in the 📝 comments below. Thanks for visiting!
Recipe
Creamy Seafood Chowder Casserole
Equipment
- Mandolin Slicer for evenly thin potato slices (optional but recommended)
- Whisk for stirring the sauce
- Small mixing bowl to combine the breadcrumb topping
Ingredients
For the scalloped potatoes
- 2 medium Yukon Gold potatoes divided, thinly sliced with a mandoline (about ⅛ inch thick)
- ½ teaspoon salt divided
- ¼ teaspoon ground black pepper divided
For the sauce
- 2 tablespoons butter to saute the onion and garlic
- 1 small onion finely chopped
- 2 cloves garlic minced
- 3 tablespoons butter to make the sauce
- 3 tablespoons all-purpose flour
- 1 ½ cups milk preferrably full fat
- 1 cup chicken broth or seafood broth
- ½ cup heavy cream
- 1 cup mozzarella cheese grated - or white cheddar, or a mix
- ½ teaspoon salt
- ¼ teaspoon black pepper
- 1 teaspoon Old Bay seasoning
- 1 teaspoon Dijon mustard optional but adds depth
For the seafood mix:
- 12 oz. (350 gm.) salmon fillet skin removed, cut into bite-size cubes
- 12 oz. (350 gm.) cod or halibut fillet cut into bite-size cubes
- 1 cup cooked crab lump or imitation, chopped
- 1 cup bay scallops or sea scallops, chopped
- ½ cup smoked salmon chopped into small pieces
For the topping
- 1 cup mozzarella cheese grated - or white cheddar, or a mix
- ¾ cup breadcrumbs panko or regular
- 2 tablespoons butter melted
For the garnish (optional):
- 1 tablespoon scallion chopped - or fresh parsley, or dill
Instructions
Prepare potatoes:
- Preheat the oven to 375°F (190°C). Lightly grease a 9x13-inch casserole dish with butter or oil.2 medium Yukon Gold potatoes
- Thinly slice the Yukon Gold potatoes using a mandoline (about ⅛-inch thick). Arrange half of the potato slices on the bottom of the greased casserole dish. Season with a pinch of salt and pepper and set aside.½ teaspoon salt, ¼ teaspoon ground black pepper
Prepare the creamy sauce and seafood:
- In a large skillet, melt 2 tablespoons butter over medium heat. Add the chopped onion and sauté for 3-4 minutes until the onion has softened. Stir in the garlic and cook for another 30 seconds.2 tablespoons butter, 1 small onion, 2 cloves garlic
- Stir in 3 tablespoons of butter to the pan. Once melted, whisk in 3 tablespoons of flour to create a roux. Cook, whisking, for about 1 minute.3 tablespoons butter, 3 tablespoons all-purpose flour
- Slowly whisk in the milk, broth, and heavy cream. Simmer and stir for 3–4 minutes until thickened.1 ½ cups milk, 1 cup chicken broth, ½ cup heavy cream
- Now stir in the cheese, salt, pepper, and Old Bay seasoning. You can also add the optional Dijon mustard at this point. Remove from heat once cheese has melted and sauce is creamy. Taste the sauce and add more salt and/or pepper to taste.1 cup mozzarella cheese, ½ teaspoon salt, ¼ teaspoon black pepper, 1 teaspoon Old Bay seasoning, 1 teaspoon Dijon mustard
- Gently fold the seafood into the sauce. Make sure the seafood is evenly coated.12 oz. (350 gm.) salmon fillet, 12 oz. (350 gm.) cod or halibut fillet, 1 cup cooked crab, 1 cup bay scallops, ½ cup smoked salmon
Assemble the casserole:
- Spoon half of the seafood mixture evenly over the bottom half of the potatoes. Top with the remaining potato slices. Season again lightly with the remaining salt and pepper, and spread the remaining seafood mixture over the top layer of potatoes. Sprinkle shredded cheese over the top.1 cup mozzarella cheese
- In a small bowl, combine the breadcrumbs and melted butter and mix well until the breadcrumbs are coated, then add the buttered breadcrumb mixture on top of the cheese layer.¾ cup breadcrumbs, 2 tablespoons butter
Bake:
- Cover loosely with foil and bake for 30 minutes. Remove the foil and bake for another 20-25 minutes, until bubbling and golden.
Serve:
- Remove from the oven and let the casserole rest for 5–10 minutes before serving.
- Garnish with chopped herbs or scallions.1 tablespoon scallion
Notes
- Slice the potatoes thin and evenly. A mandoline is the best for this! It ensures the potatoes cook through without needing to be parboiled.
- Don’t overcook the sauce. Once it thickens and the cheese is melted, remove it from the heat. Overcooking can cause it to separate.
- Taste the sauce before assembling. Adjust salt, pepper, or seasoning before mixing in the seafood. It’s just easier to balance now than later.
- Make sure to layer potatoes twice! This ensures that every bite has seafood and potatoes.
Comments
No Comments