Fish Casserole - Recipes From A Pantry (2024)

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A super easy gluten free baked Fish Casserole recipe which combines creamy mashed potatoes, lean fish, and quick-cooking veggies into this classic comfort food.

Suitable for people following a gluten free diet. Post includes Weight Watchers points.

Seafood freezer meals are the epitome of comfort food, and this creamy baked fish casserole is a classic dish perfect for Sunday lunches with the family, a filling summer lunch, easy weeknight suppers, and special occasions such as Easter, Christmas, and Father’s Day.

Nothing says comfort food better than a big old helping of homemade Gluten Free Baked Fish Casserole. Thissimple dishcan bemade ahead of timeandis beyondvery easy to whip upinto themost creamy, filling and decadent homemade Fish Casserole recipe.

Serve it with Smashed Brussels Sprouts, Smothered Green Beans, or any of your favorite side dishes for a satisfying meal that everyone will love.

What makes this fish potato casserole stand out is that it’s also gluten free. This recipe uses cornstarch (cornflour) instead of flour to make the roux that thickens up the casserole sauce.

And, I have also used a variety of fish to complete this Healthy Seafood Casserole, rather than just sticking to one fish or the other. This is one of those ‘the more the merrier’ kinda recipes.

Why Make This Baked Fish Casserole Recipe

• It’s flavorful and adaptable. Fish can be seasoned and flavored in various ways, making it adaptable to different taste preferences and cuisines.
• It’s comforting. Seafood freezer meals and casseroles often have a comforting, homey appeal, making them perfect for cozy dinners. It’s an easy meal that will be a family favorite.
• It’s healthy. Fish is a lean source of protein and is rich in essential nutrients like omega-3 fatty acids, which are beneficial for heart and brain health.

Making casseroles is a great way to save time and money. Check out thesecasserolesfor more flavorful ideas your family will love.

Ingredient Notes

• Potatoes – Use your favorite potatoes to make mashed potatoes as a topping for the casserole. You can use different types of potatoes like russet, Yukon Gold, or red potatoes. Sweet potatoes could also be used for a unique twist.
• Butter – I opt to use dairy-free butter, but you can use regular butter if you’re not following a dairy-free diet. Alternatively, use coconut oil or olive oil for a dairy-free option.
• Plant-based milk – Plant-based milk is used to make the mashed potatoes creamy and as a part of the casserole sauce. Any type of plant-based milk like almond, soy, oat, or cashew milk can be used. Regular dairy milk is an option if you’re not going dairy-free.
• Olive oil – Use your favorite light, neutral flavored cooking oil, such as extra virgin olive oil.
• Green Onions – Green onions add a mild onion flavor to the casserole. You can use regular onions or chives as a substitute for green onions.
• Cornstarch – Cornstarch is used as a thickening agent for the casserole sauce. You can substitute arrowroot starch or potato starch for cornstarch if desired.
• Dijon Mustard – Dijon mustard adds a tangy flavor to the casserole sauce. You can use yellow mustard or whole-grain mustard as a substitute.
• Ground Nutmeg – Nutmeg adds a warm, aromatic flavor to the sauce.
• Anchovy Fillets – Anchovy fillets provide a savory, umami depth of flavor to the casserole. If you don’t like anchovies, you can omit them or use a vegan fish sauce substitute.
• Fish Pie Mix – Fish pie mix typically includes a variety of seafood such as white fish, salmon, and smoked fish. You can use a mixture of your favorite seafood like cod, salmon, shrimp, or any other fish you prefer. You can also use fish fillets that have been cut into bite-sized pieces.
• Baby Spinach – Baby spinach adds a fresh and vibrant element to the casserole. You can use other leafy greens like kale or Swiss chard if preferred.
• Frozen Peas – Peas provide sweetness and color to the casserole. Fresh peas or canned peas can be used instead of frozen peas.

How To Make Fish Casserole

Get complete ingredients list and instructions from the recipe card further below.

1. Boil and mash the potatoes with some plant-based milk and dairy-free butter, then set aside.
2. Melt butter in saucepan, add in and sauté greenonions before adding cornstarch.
3. Slowly whisk in the plant-based milk, then bring to a rolling simmer, stirring continuously until the sauce is thick.
4. Switch off the heat, then stir in mustard, nutmeg, anchovies, fish casserole mix, baby spinach, and peas before transferring to a prepared casserole dish or baking dish.
5. Top with mashed potatoes and bake for 25 minutes in the hot oven until golden and the mixture is bubbling.

Pro Tips

• If you are starting with whole fish, then make sure to cut into similar-sized chunks so they cook at the same time.
• If you have less fish than the recipe calls for, you can bulk up your fish casserole with extra veggies.
• Choose fresh fish, vegetables, and herbs to ensure the best flavor and texture in your casserole.
• Season each layer with salt, pepper, and any desired herbs or spices to enhance the overall flavor.
• Ensure you’re using an appropriately sized casserole dish. It should be large enough to comfortably fit all the ingredients without overflowing.
• Always preheat the oven to the specified temperature in the recipe to ensure even cooking.
• You want the casserole to be a nice golden brown. If the casserole tends to brown too quickly on top, cover it with aluminum foil for part of the baking time to prevent excessive browning.
• Allow the baked fish casserole to rest for a few minutes after removing it from the oven. This helps the flavors meld together, and it will be easier to slice and serve.
• Baked casseroles are best served hot, so try to time your meal to be ready when the fish casserole comes out of the oven.
• Add a squeeze of fresh lemon juice.

Recipe Variations

• Swap the veggies. Feel free to add more quick-cooking vegetables like green beans and sweetcorn.
• Add shrimp. You can also add shrimp to the chopped fish mix.
• Swap the potatoes. Try using mashed sweet potatoes instead of regular mashed potatoes.
• Add fresh herbs. Fresh herbs like parsley, dill, or chives can be added at the end for a burst of freshness and color.
• Top with pastry. If you prefer, you can make this a fish pie with pastry. To do so, simply skip the mashed potato and cover the fish casserole mix with puff pastry and then bake. Just make sure you are using a gluten-free pastry.
• Add cheese. If you want to upgrade this to a cheesy seafood casserole you can. Simply take the casserole out after about 15 minutes and top with lots and lots and lots of cheese. Then return to the oven until cook time is done. Parmesan cheese is a tasty choice but you can also use cheddar cheese.

Prep and Storage

• Prep – Defrost frozen fish and prep all of your ingredients.
• Store – Leftover casserole should be stored in an airtight container in the fridge and consumed in 2-3 days.
• Freeze – Just assemble, and instead of cooking right away, cover tightly and freeze. If you are going to freeze it, then start with fresh fish rather than frozen fish. A perfect make-ahead meal prep solution!
• Reheat – Preheat the over to 275 degrees F / 140 degrees C. Add a splash of milk or water to the casserole and cover with foil. Reheat for about 12-15 minutes till warmed through.

FAQs

More Gluten Free Fish Recipes

Want more gluten-free fish recipes? Then try these tasty dishes:

• How Long To Bake Salmon At 350.
• Crispy Air Fryer Fish.
• Juicy Air Fryer Salmon Fillets.
• Air Fryer Salmon Patties.
• Air Fryer Cod.
• Air Fryer Tilapia.
• Frozen Salmon In Air Fryer.

Serve With:

This baked fish casserole makes a great meal by itself but if you want to stretch it out a little bit, then feel free to serve any of these sides:

• Brussels Sprouts Gratin.
• Instant Pot Steamed Broccoli.
• Instant Pot Glazed Carrots.
• Cucumber Tomato Salad.
• Easy Spinach Salad.

• A good set of saucepans for even cooking.
• A very handy casserole dish.
• The best ever sea salt flakes.
• A set of spices to add different flavors to your food.
• For the best tools to help make your recipe even easier and more successful, check out my collection of the Best Kitchen Tools on Amazon.

Weight Watchers Points

There are 7 Blue Plan SmartPoints in one serving of this.

Thank you for reading my fish potato casserole recipe post. And please come visit again as I continue to slice, dice and dream up affordable Air Fryer recipes, Instant Pot recipes, Southern Recipes, and more. Thanks for supporting Recipes from a Pantry, food blog.

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