This is a one-pan meal with fish baked in cream on top of a potato gratin with a golden crunchy topping. It’s a cross between a casserole, gratin and a pie. Fabulously cosy, rustic, oven baked fish recipe that’s effortless yet company worthy!

Creamy baked fish on potato gratin
This dish gives off very French-country vibes. Which, in hindsight, is rather unsurprising given it’s a recipe that our very own Chef JB just casually threw together one day. We ate it, loved it so much, declared it was “website-worthy” then proceeded to remake it…oh, I don’t know. Maybe 10, 12 times before we were fully happy with it and closed out all the “what ifs”?
Basically, it’s a creamy potato gratin, heavy on the leek (or onion), with fish that is baked on top at the same time, covered in a crunchy golden breadcrumb topping. So essentially, the breadcrumb topping acts as a lid, keeping everything steamy and succulent as the fish bubbles away in the creamy sauce while the gratin soaks up the tasty fish juices.
It’s just an all-out cosy dish of deliciousness!



Ingredients
Here’s what you need to make this:
Best fish

This recipe is best made with the more delicate white fish fillets that are around 2 cm (0.8″) thick. We don’t want fillets too thin else they will overcook. (UPDATE: Readers have made and loved it with salmon – read feedback in comments section!)
Our favourite fish to make this with is barramundi which is a popular Australian fish. Here are some more fish with similar cooking characteristics that will work great:
barramundi (pictured), John Dory, snapper, basa, jewfish, blue eye cod (trevalla), tilapia, cod, halibut, pollock, hake, and salmon (readers have tried and loved – see recipe comments!).
Remember, the shape of fish means that you get thick cuts from the main body as well as thin cuts from towards the tail. Opt for the thicker cuts, aiming for 2cm/0.8″ thick. Pictured above is barramundi which is a thicker fish so we used the tail.
Skin on or off? Either is fine, it really won’t affect the bake time. But the skin won’t be crispy. If this is a turn-off for you, just eat the flesh and leave the skin.
Fish to avoid
I recommend avoiding:
Fish that dry out easily when cooked – Like swordfish, tuna, bonito, kingfish, marlin, mackerel. Unless you’re extremely careful they can become dry inside so are very prone to overcooking in the oven. I feel these fish are (mostly) better in raw/rare form such as Ceviche, Poke Bowls, Tartare (also see Tuna Steak);
Oily, “fishy” fish – Like mullet and sardines (try this recipe for sardines!).
For the potato gratin and creamy sauce
And here’s what you need for the rest of the dish:

Potatoes – Floury (starchy) and all-rounder potatoes work best to achieve a lovely potato gratin flavour.
– Australia: the cheap dirt-brushed potatoes sold everywhere (called Sebago) are ideal
– US: Russet
– UK: Maris PiperLeek – Flavour base for the gratin. Feel free to substitute with a standard onion!
Garlic – Flavour base.
Chardonnay or other dry white wine – This gives the sauce depth of flavour. Without, it tastes more one dimensional and like it’s missing “something”. Chardonnay is my favourite but any dry white wine that’s not too sweet or too woody will work fine. Non alcoholic substitute – More vegetable stock.
Vegetable stock/broth – For semi braising the potatoes in a flavoured broth, tastier than using just water!
Butter – For pan sautéing the potatoes before finishing them off in the oven.
Panko, parmesan and olive oil – The crunchy topping!
How to make Creamy Fish on Potato Gratin
This is a one pan meal that starts off on the stove and is finished in the oven. It would be handy if the whole dish could just be done in the oven, but we tried and the flavour was not as good. Whereas using the stove-to-oven method makes it company-worthy good!

Crunchy topping – Mix the panko and olive oil together, then stir through the parmesan.
Sauté the leeks and garlic, then cook the sliced potatoes for 6 minutes or until they are partially cooked. During this step, the potatoes absorb the flavour of the leek and garlic which is what makes the gratin so good!
Braise the potatoes firstly in wine for 1 minute (simmer rapidly to almost fully reduce to cook out the alcohol) then the vegetable stock for 1 1/2 minutes until reduced by half.
Top with fish pieces (which we first sprinkle with salt and pepper). Then pour over the cream, aiming for as much coverage as possible.
Topping – Sprinkle the entire surface with the crunchy topping.
Bake for 30 minutes – I PROMISE THE FISH DOES NOT OVERCOOK!! You would think it does, but it doesn’t. All that creamy goodness under the breadcrumb topping keeps everything moist and succulent!
Broil/grill 4 minutes – Then to finish it off, I like to give it a quick 4 minute blast under the oven grill/broiler to give the topping lovely colour.
Rest 5 minutes – Place on the counter and let it rest for 5 minutes before serving. Don’t skip this step! This is when the juices in the fish gets reabsorbed into the fibres so when you cut into the fish, it stays in the fish flesh (and ends up in your mouth) rather than running out onto the plate.


What to serve with Creamy Fish on Potato Gratin
All you need to finish off this meal is a fresh, crisp salad to serve on the side. Just toss leafy greens in French Dressing, or if you’re cooking for company, try the French Bistro Salad. On theme with the French-ish vibes going on in this dish!
I also wouldn’t say no to some crusty bread for mopping the plate clean. And for dessert – anyone for a pile of fresh baked Madeleines? Fast becoming a go-to for dinner parties because the batter is made in advance (you can even freeze it!) and stored in piping bags or jugs. Then it literally takes 2 minutes to pipe into the pan and 10 minutes to bake. How good is that!!! – Nagi x
Suggested sides



Watch how to make it
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Creamy fish on potato gratin
Ingredients
- 4 x 160g/5oz white fish fillets , ~2cm / 0.8" thick, skinless (barramundi, snapper, tilapia, cod, salmon – Note 1)
- 1/2 tsp cooking/kosher salt
- 1/4 tsp black pepper
Potato gratin:
- 3 tbsp / 50g unsalted butter
- 2 large leeks , white and pale green part only, washed, cut in half lengthways, sliced 5mm / 0.2" thick OR 2 onions (Note 2)
- 3 garlic cloves , minced
- 2 medium starchy potatoes (250g / 8oz each), peeled (Note 3)
- 3/4 tsp cooking/kosher salt
- 1/2 tsp black pepper
- 1/2 cup dry white wine , any type, sub more veg stock (Note 4)
- 1/2 cup vegetable stock/broth , low sodium
- 1 cup thickened/heavy cream
Crunchy topping:
- 3/4 cup panko breadcrumbs
- 2 tbsp extra virgin olive oil
- 1/4 cup parmesan , finely shredded
Instructions
- Preheat the oven to 180°C/350°F (160°C fan) with a shelf in the middle.
- Potatoes – Cut the potatoes into quarters, then sliced 4mm / 1/6" thick. Place cut potato in a large bowl of water (prevents from going brown, removes excess starch so it cooks quicker). Drain before use.
- Crunchy topping: Mix panko and olive oil in a bowl. Then stir in parmesan.
- Season fish: Sprinkle salt and pepper on both sides of the fish fillets. Set aside.
- Sauté – Melt butter in a large oven-proof skillet (30cm/12") over high heat until foamy. Add leek and garlic, then cook for 3 minutes.
- Sauté potatoes – Add potato, salt and pepper. Cook for 6 minutes, stirring regularly. The potatoes should be half cooked at this stage.
- Reduce wine and stock – Pour in white wine. Simmer rapidly until it is mostly evaporated – about 1 minute. Pour in stock, then simmer for 1 1/2 minutes or until reduced by half.
- Top with fish – Turn the stove off. Place fish on top of the potatoes, presentation side up. (Note 1) Pour cream all over, aiming for full coverage. Sprinkle with panko breadcrumbs.
- Bake for 30 minutes – I know this sounds like a long time but the fish stays succulent!
- Colour topping – Switch to the oven grill (broiler) on high and move the skillet up to the top shelf. Grill/broil 4 minutes or until golden.
- Rest – Remove and rest for 5 minutes, then serve! Eat the fish and gratin together with each mouthful for maximum eating pleasure!!
Recipe Notes:
– Australia: the cheap dirt-brushed potatoes sold everywhere (called Sebago) are ideal
– US: Russet
– UK: Maris Piper 4. Wine adds more flavour into this dish but doesn’t make it taste winey because we cook the alcohol out. Substitute with more vegetable stock. Leftovers will keep for 3 days in the fridge. Not suitable for freezing. Nutrition per serving.
Nutrition Information:
Life of Dozer
The best handbag a girl can ask for!

So disappointed as your recipes are usually spot on. This was bland and too long a time to bake fish – ruined a beautiful thick piece of cod!
Well I just made this with gummy shark as the fish and it is an A+ winner. Sensational! And incredibly easy. As it was the first time I have cooked it, it took much longer than Nagi’s estimates, but it will be much quicker next time. I served it with peas, because I think something creamy like this needs a fresh green to cut it a bit. 5 stars from me and also my wife.
Thank you for all your recipes and especially the detailed presentation.
OMG! I made this yesterday and it was soooo good! I used salmon and it cooked well. This will be on repeat for sure
This fish dish is amazing – so tasty and easy to cook too. My husband and I both loved it. All your recipes are great and believe me I have tried quite a few. Once again thanks Nagi.
This was fantastic and much faster to make than a normal gratin. I used 1 Russet and 1 Sweet potato and Cod, it all worked so well! Wonder if I can sneak a veggie in there somewhere…
Hi Nagi. I made this last night using snapper and it was delicious. With Edith Piaf playing in the background we all enjoyed a lovely French dinner.
Another super awesome dish, thank you so much Nagi. You never let me down. I did this with salmon and a dash of mustard in the cream,. We loved the salmon and agreed that a milder white fish would not be as tasty for us.
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Great to hear it was good with salmon Sherryl! I wasn’t sure if it might be a little too strong 🙂 N x
I made it with salmon as it was the fish we had in the freezer. Made it exactly as your video or recipe…we loved it, delicious, and again one dish…if you only knew how much I appreciate your recipes, I wish you a long life!
I love that you tried this with salmon Lyse! I’ll update the recipe with this tip. Glad you enjoyed it! N x
Hi Nagi, after 24 years at my workplace, I cook lunch for my colleagues every Tuesday as I believe in giving back. I cannot wait to try the latest creamy fish gratin potatoe recipe. I have never had a complaint and have always followed your recipes. Last year I sufferd a brain aneurysm with less than 30% survival, but I am back cooking up a storm thanks to you Nagi. I have gifted many of your recipe books too. Forever grateful for your work xx
I’m sorry to hear about your health problems Linda, but so glad you are BACK with a vengeance!! Hope your colleagues enjoy the dish – lucky people! N x
Another amazing recipe. They all make me a pro in the kitchen, its unheard of.
I’m so glad you enjoyed it Mylin! N x
I want to eat this so much! I need to convince the fam bam. It’s exhausting!
Make it and let them smell it – THAT will convince them!! N xx
I’ve followed you and cooked so many of your delightful recipes for quite some time. This is amazing. My fav’s (potatoes, seafood, crunchy top). Followed your recipe leads, used onion (no leeks), used crabcakes bought for a different recipe (no fish) and used full fat coconut milk (no cream). I ate half the recipe by myself (ashamed look on face). You are an inspiration (which I know comes from Dozer) and THANK YOU FOR THIS AMAZING DISH!
I’m so thrilled you enjoyed this Jean, thank you so much for sharing your feedback!! N xxx
WHAT ABOUT THE MOVE????
Ha ha I want to know about the move as well!
I’m going to do a big update post next week, I promise!! 🙂 So much happening right now… N xx
Hi Nagi, I am about to try another of your wonderful recipes. The recipe for Creamy Fish on a Potato Gratin does not provide a Nutrition value. Was this forgotten or too hard?
And yes, Dozer is the perfect handbag! I have had four Golden Retrievers over the past 30 years! Thank you. Hugs to Dozer, too.
Would love the nutrition please
Hi Nagi,
Can’t wait to try that great looking recipe! I’ll take that “handbag” any day!!!
Love to you & Dozer
Can i use frozen fish fillets to make this..? Cook from frozen?
Hello Nagi and Chef JB,
Nice riff on a fish parmentier. My meal for Friday. Thank you🐠
My husband won’t eat fish! Do you think this would work with chicken breasts?