A creamy, quick, and easy Keto Seafood Casserole is the perfect weeknight meal since this keto recipe uses frozen seafood. A savory blend of seafood and rich cheeses bakes in this delicious pie that’s hearty enough to satisfy even the hungriest of crews. Serve for dinner, lunch, or brunch!
Keto Seafood Recipes
With the traditional "7 fishes" dinner around the corner as well as "Fish Fridays", I knew I needed to come up with some keto seafood recipes. This keto seafood casserole is an easy keto dinner idea, just like my popular Air Fryer Spicy Bay Scallops and my Easy Keto Ahi Tuna Poke Bowl
And, just because it's made out of seafood doesn't mean it can't be budget-friendly. By using either a bag of frozen mixed seafood or a bag of frozen salad shrimp, this keto seafood pie costs under $10 to make!
Call it a keto seafood casserole or a keto seafood pie, this keto seafood recipe is an absolute winner!
Why this recipe works
- Easy - This is a perfectly easy keto dinner idea that comes together quickly and with little hands-on time. Simply pull out the frozen seafood in the morning and by the time you get home from work, all you will have to do is drain it!
- Budget-Friendly - By using frozen seafood, you can save yourself a ton of money. Frozen seafood works well in this recipe since it is added to a variety of different flavours and textures
- Healthy - Low carb and gluten-free, this keto seafood casserole is packed with antioxidants and healthy fats
- Leftovers - No need to worry that this keto seafood pie makes enough for 8 since you can easily heat up the leftovers for lunch or dinner the next day!
This keto casserole only requires a couple of ingredients that you can find at nearly any and all grocery stores.
- Seafood - You can use frozen seafood and simply thaw and drain it before using it. I have used both frozen mixed seafood as well as frozen salad shrimp.
- Cheese - You can use any type of cheese that melts such as sharp Cheddar cheese, Havarti, Swiss or Provolone. I do not suggest mozzarella as it may be slightly too bland for this simple recipe. I also do not suggest using packaged shredded cheese as this style of cheese contains anti-caking ingredients that do not allow it to melt as well.
- Cream cheese - Use any type of cream cheese (except for fat-free). Make sure that you soften the cream cheese in order to be able to blend the cream cheese into the egg mixture
- Mushrooms and Onions - You will need to quickly sautee the mushrooms and onion in order to remove some of the moisture as well as to bring out the flavour of these two ingredients
- Keto Bisquick mix - You can find detailed instructions for making a large batch of my Keto Bisquick mix here.
- Butter - You will need to melt the butter before blending it into the eggs
- Eggs - Make sure that your eggs are at room temperature
- Spices - I used salt and nutmeg but feel free to use your favourite seasoning blend instead.
See the recipe card for quantities.
Just like most of my recipes, there are only a few steps (and only a few dishes!) in this keto seafood recipe!
Whisk together the eggs, melted butter, seasoning, and the keto Bisquick
Whisk in 1 cup of shredded cheese of choice and set the bowl to the side.
In a large skillet that has been sprayed with cooking spray, sautee the sliced mushrooms and onion until nice and brown.
Add in the thawed and drained seafood and cook
Cook stirring constantly until the seafood just begins to turn opaque
Add the seafood, mushroom, and onion mixture to the egg bowl along with ¾ cup of cheese and stir to incorporate. (Reserve the ¼ cup of cheese to sprinkle on the top)
Carefully pour the mixture into a baking pan and place the pan on a rimmed baking sheet.
Bake until the casserole has set and has turned a nice golden brown colour on top.
Allow the casserole to rest for about 10 minutes before serving.
Hint: You do not have to use a rimmed baking sheet but it does make moving the keto seafood casserole in and out of the oven easier as well as will catch any overflow of the keto seafood pie.
Although I have not made this keto seafood casserole with all these substitutions, I am fairly confident that each substitution should work just fine.
- Seafood - feel free to use shredded chicken or leftover beef instead
- Mushroom and Onions - saute diced carrots, celery, and/or peppers instead
- Vegetarian - Omit the seafood completely and double all the remaining ingredients instead.
This keto seafood pie can be altered to suit your favourite seafood spice blend
- Spicy - add creole seasoning, hot sauce, or blacken seasoning
- Deluxe - add some cooked bacon crumbles on top
- Clams - use some canned clams instead for a clam chowder version
See my Best Ever Clam Chowder recipe for a delicious seafood soup!
I made this keto seafood casserole using a 9-inch ceramic pie plate (but a 10-inch will work as well as an 8-inch) as I found it to be the prettiest way in terms of presentation. However, any 9 x 9-inch baking dish or casserole dish will work just as well.
Just remember that glass, metal, and ceramic heat differently so since I used a ceramic pie pan, the baking time may be longer than if you use glass or metal.
Store the leftover seafood pie in an airtight container in the fridge for 5 days. To reheat the keto casserole, simply place it in the microwave for about 1 minute.
If you use a different type of casserole dish or a different size, the baking time will vary. Luckily, since we are cooking the seafood first, there is no need to worry about whether or not the seafood has been thoroughly cooked. To make sure the keto seafood casserole is fully cooked, the pie should be firm when pressed in the center and not jiggle.
What is the key to making the best casserole?
You have to take the time to actually cook the ingredients before baking them. If you do not, the casserole will be too soggy.
What are the key ingredients for this casserole?
You typically want a protein source, some vegetables, and a binder. If you want to change any of the ingredients in a casserole recipe, just keep these 3 things in mind.
What can you serve with this seafood casserole?
You can eat this keto seafood casserole with a side soup or salad. Or serve it alongside some keto bread or crackers.
Do I need to use the keto Bisquick?
Yes. The keto Bisquick acts as a binder. To make a "cheater" version, simply combine 1 cup of almond flour with ½ teaspoon of baking powder and ¼ teaspoon of salt. Feel free to add any additional spices such as garlic or black pepper.
- 16 oz (1 pound) frozen mixed seafood, thawed and drained or frozen salad shrimp, thawed and drained
- 2 cups shredded sharp natural Cheddar cheese (or Swiss, Havarti or a combination), divided
- 8 oz sliced mushrooms
- ½ onion, diced
- 1 cup Keto Bisquick mix
- ¼ cup unsalted butter, melted
- ¼-½ teaspoon salt *
- ½ tsp nutmeg
- 4 eggs
- Preheat the oven to 350 degrees F. Grease a pie pan (or another baking dish) and place it on a rimmed baking sheet. Set it to the side.
- In a large bowl, combine the keto Bisquick, melted butter, salt, nutmeg, and eggs and whisk until combined. Add 1 cup of cheese and stir to combine. Set the bowl to the side.
- In a large skillet sprayed with cooking oil, add the onion and mushrooms. Cook on medium-high heat until they begin to brown, about 5 minutes. Add in the thawed and drained seafood and cook, stirring constantly, for about 1-2 minutes or until the seafood starts to turn opaque. Remove the skillet from the heat.
- Add the mushroom/onion/seafood mixture to the Bisquick/egg bowl and stir to incorporate. Add ¾ cup of cheese to the mixture.
- Carefully pour the mixture into the pie pan and sprinkle with the remaining ¼ cup of cheese. Bake on the middle rack for about 30-40 minutes or until the top begins to brown and the center is set.
- Remove from the oven and allow it to cool slightly for 10 minutes before serving.
- *I do not like to add too much salt to my recipes as you can always add more after serving but you can not remove it! So, if you use a saltier cheese, only use ¼ teaspoon but if you use a cheese like mozzarella which is not as salty, feel free to use ½ teaspoon.
- Baking time varies due to the type of pan you use
- see post for keto Bisquick substitution
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Breakfast, Brunch, Dinner, Lunch
- Method: Baking
- Cuisine: American, Seafood, Casserole
- Diet: Gluten Free
- Serving Size: 1 slice
- Calories: 250
- Sugar: 1
- Fat: 18
- Carbohydrates: 3
- Fiber: 0.5
- Protein: 18
Keywords: casserole, pie, brunch, easy recipe, keto, low carb, gluten-free, frozen seafood, mixed seafood, fish fry