This easy keto fish pie is comfort food at its best. It has a deliciously creamy filling and a cheesy cauliflower mash topping.
Fish pie is a classic British family dinner and one of the first dishes I learned when I first moved to London.
The traditional recipe consists of a variety of fish in a white sauce that is topped with mashed potatoes. You then bake it in the oven until the topping is crisp and golden.
It is very simple to turn it into a proper low carb fish pie. I got my inspiration from two different recipes in Vickie De Beer's amazing Low Carb Diabetes Cookbook.
The most important change is to substitute the potato mash with mashed cauliflower. I promise you won't taste the difference. My daughter even declared: "I love the potato mash!"
We make this pie regularly and everyone always wants to come back for seconds.
🌟 Why You'll Love This Recipe
- Creamy and comforting
- Ready in just 1 hour
- Freezes well - great for meal prep
- Keto friendly - only 8.1g net carbs per serve
Ingredients
Here are the ingredients you'll need:
For the filling
- White fish fillets. I used hake and cod.
- Onion. Finely chopped.
- Garlic. Fresh is best, but you could replace it with garlic powder.
- White wine. Use a dry wine. Can be substituted with fish stock, vegetable or chicken broth.
- Heavy cream. This is double cream here in the UK.
- Zucchini. Should be grated. This thickens the sauce.
- Lemon zest.
- Fresh parsley and chives.
For the mash
- Cauliflower. Make sure it is very fresh. If you only have frozen cauliflower or cauliflower rice, squeeze out all liquid after cooking with a cheesecloth or dish towel.
- Butter
- Sour cream or cream cheese
- Cheddar cheese
- Chives
- Nutmeg and salt
All amounts and details are in the recipe card at the bottom of the post.
Instructions
This is a very simple recipe that even beginners can master easily. Here are the basic steps:
Step 1: Steam, boil or microwave the cauliflower until soft. Use the tips in my post on keto mashed cauliflower. Drain well.
Step 2: Put the cauliflower florets in a food processor. Add the softened butter, soured cream, cheddar, chives, nutmeg and salt. Blend until smooth. Set aside while you make the filling.
Step 3: In a large skillet or frying pan, sautƩ the onions and garlic. Fry until soft and translucent over a low heat.
Step 4: Add the white wine. Cook over a high heat until reduced by half.
Step 5: Add the zucchini, cream, lemon zest and herbs. Season with salt and pepper and let simmer for a while.
Step 6: Put the fish fillets in a casserole dish and pour over the sauce.
Step 7: Put the fish fillets in a casserole dish and pour over the sauce. Spread the cauliflower mash on top and bake.
Serve with a crisp green salad, a side or green beans or enjoy all on its own.
Expert Tip
It is essential that the cauliflower is very soft, but not watery. If you have steamed it, pat it dry. If you have boiled it, drain the water and then put it back in the pot. Let any residual moisture cook off, without letting it burn.
Don't like cheese? Make the cauliflower mash from my keto cottage pie recipe.
Recipe FAQs
Any white fish works, as well as salmon or prawns or even lobster. You can also try a smoked fish.
Of course. Simply fill into single serve ramekins.
For a dairy-free version, use a dairy-free cream instead of the heavy cream. Use olive oil instead of the butter in the cauliflower mash and add either a vegan cheese or nutritional yeast for a cheesy taste.
Single cream (or half and half) is more watery than heavy cream or double cream. I don't recommend it.
Storage
Refrigerator: Store Keto fish pie in the fridge for up to 3 days.
Freezer: Freeze for up to 3 months. Thaw overnight in the fridge, the reheat in the oven or in the microwave.
If you love fish recipes as much as I do, also check out my Low Carb Keto Fish Tacos!
More easy dinners
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Recipe
Low Carb Keto Fish Pie
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary.
Ingredients
For the filling
- 1 onion chopped
- 2 garlic cloves chopped
- 1 cup dry white wine (250ml)
- 1 cup double/heavy cream (250ml)
- 3 medium zucchini 550g, grated
- grated lemon zest from 1 unwaxed lemon
- handful of fresh parsley and chives chopped
- 1.75 lb hake and/or cod fillets (800g) without skins
- pepper and salt to taste
For the cauliflower mash
- 1 very large or 2 smaller cauliflower heads 700g
- 3 tablespoon melted butter 40g
- Ā½ cup soured cream or cream cheese, (125g)
- 1 cup cheddar shredded (125g)
- 1 tablespoon chopped chives
- Ā¼ teaspoon nutmeg
- salt to taste
Instructions
Cauliflower Mash
- Separate the cauliflower into florets and steam/ boil/ microwave until soft. Follow the tips in my keto mashed cauliflower recipe.
- Add the butter, soured cream, cheddar, chives, nutmeg and salt. Blend in a food processor or with an immersion blender until smooth.
- Preheat oven to 200 Celsius/400 Fahrenheit (electric) or 180C / 360 F fan.
Fish filling
- Fry the onions and garlic in olive oil over a low / medium until soft and translucent, around 3 minutes. Do to burn.
- Add the white wine. Turn up the heat to high and reduce by half.
- Add the grated courgettes, cream, lemon zest and herbs and simmer for 5 minutes. Season with salt and pepper.
Assembly
- Put the fish fillets in a casserole dish and pour over the sauce.
- Spread the cauliflower mash on top and run a fork over the top to make lines.
- Bake for 40 minutes or until the top is browned.
- Sprinkle with some fresh parsley and serve.
Judith J Chandonnet
"forgot" to buy zucchini, which was okay since I don't really like it! Used grated carrot instead. It was very yummy!
Edie
I made both our fish pie and your fish cakes for my daughter in law who is ill and special dietary needs. After four years I persuaded her to try fish and she loved it. Thank you it's a hit.
Do you have a sauce suitable for fish cakes too? It will be frozen fish cakes so if a sauce is ok to add to a container in portions it will help.
Thnk Katrin
Ruth
I had to tweak the recipe slightly as one of my guests is allergic to alliums, so I replaced the onions with celery and fennel. Even so, it was delicious. The whole thing got polished off. It was quite a lot of work, so in advance of next time, I made the sauce, and the cauliflower mash and frozen them, so will be easy to put together.
Tanja
Fish pie is something I have never had before. Loved the taste, my hubby did not! I went back for seconds! The cauliflower mash is something that I will have to get used to but it was good! I used cod for mine but if I can find haddock or rockfish I will try it with that next go. I think I will make the mash separate from the fish next time and see what hubby thinks of it then.
Momofgirlswcurls
If I used half an onion do you think that would cut the carbs? My daughter is trying 20 carbs a day. Thank you.
Katrin NĆ¼rnberger
Yes, it would. Onion is fairly high in carbs. Replacing the wine with more stock will also lower the carbs.
Charmian
Hi Katrin, The recipe looks great but I have IBS and Diverticulitis and follow the Low Fodmaps diet which really helps. Iād love to do Keto but cauliflower is a no no as itās high Fodmap and itās used as rice replacement in so many savoury dishesā¦. Do you have any suggestions as to what I could replace it with?
And is there any other flour except almond or coconut that could be used in the baking for the same reasons. I think 24g almond flour is the max in one meal! Many thanks
Katrin NĆ¼rnberger
You could use rutabaga or celeriac mash instead. Both are higher in carbs, but you may tolerate them better. Instead of almond flour, a 50/50 mix of sunflower seed flour and sesame seed flour usually works well. Coconut flour cannot be replaced 1:1 because it's more absorbent than any other flour I know. Hope this helps!
Jo
Can you freeze this?
Katrin NĆ¼rnberger
Yes, this fish pie freezes well.