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:
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This was just incredible! We all absolutely LOVED it. Husband declared it his new favourite – seems every recipe I make from this site is his new favourite 😂. Thank you Nagi for such delicious recipes.
Terrific.
I used Basa Fish x2 fillets.
I used coconut milk can, not cream.
1 x leek, 1 x small onion.
-I had to move the potatoes to a microwave dish mid cook, (maybe I added too many spuds?) they wouldn’t soften.
I added some stock and micro spuds until soft, worked well,
Returned to stovetop pan, continue recipe.
I added lots of fresh ground black pepper & a little salt to every step. Yum!
I was nervous about the 30min oven time.
Just perfect!
Winner here!
BIG FAN of Nagi but I have to say this recipe far exceeded my expectations! My husband does a LOT of fishing and I’m forever trying to find new ways to cook his fish. Don’t hesitate to try this dish – it’s a lot more than it looks!!!! You have turned me into a good cook (@ 65!!) – thanks Nagi!!!! xoxoxo
Yummm, scrummm – the perfect mid week family dinner. Thank you Nagi!
Thank you for yet another winner dinner. I made it with halibut and 100% to recipe. Simply perfect (and easy).
You are the best!
Ursula
Made this tonight with salmon as I couldn’t source barramundi and I was so good. Will definitely made this again.
This dish is sensational. Making twice in one week using salmon portions. Highly recommend!
Another absolute winner. What an awesome, easy to make, fish. Will be on the menu each week with us!
Thanks Nagi, you’re simply brilliant!
Oops – forgot the star rating – a clear 5 stars!
Made this the other night with barramundi and it was absolutely delicious! I didn’t have an oven safe frying pan, so cooked up to step 7 in a frying pan on the stove and transferred it to a casserole dish before step 8. It worked well. I also found I didn’t need to grill it at the end as it was already nice and golden after baking.
Hi! I made this for dinner this evening and WOW so delicious! I have Nagi’s cookbook – love it! So far, every recipe has been easy and delicious! Thank you Nagi!
This dish is absolutely fabulous! I used monkfish and it was divine! It’s a pleasure to cook your recipes and know that they are always a success!
Cooked this for dinner tonight and it was absolutely fabulous. Used barramundi and didn’t have any wine so doubled up on vegetable stock. Just a really yummy dish, only needed a green salad with it. Definitely a keeper!
Absolutely amazing!!! And so simple to prepare. We aren’t really fish eaters, but my hubby remarked “this is a winner”
Thanks Nagi xo
Amaaaazing…my hubby said this is definitely a winner, and he’s not a fish fan…so yum
wonderful. very different and delicious!! easy to make, too.
I made this and (for once) religiously followed the recipe because it seemed a little unusual and I decided to ‘trust the recipe’. The result? Absolutely delicious! The recipe has been moved to my ‘Keep’ folder and I know I will be making it regularly. I loved the flavour of the leeks coming through, and the fish was moist and held together really well. I used Barramundi, skin on.
I thought the cream sauce with leek and potato was delicious and made dish with cod. I did think it was a little bland and will add some spices next time I make. Thanks for the recipe!
Thanks, Nagi! Made this for dinner last week, and even my pickiest eater liked it 🙂 cooked the leeks and potatoes in a pan on the stove before transferring them to an oven-proof dish with the fish. Turned out lovely!
In other news, YOUR COOKBOOK ARRIVED! I’m so excited!
Thanks Nagi, another keeper!
Used Ling as that was all that was available in anyway suitable, succulent, creamy and tasty.
I cooked the veges, wine and stock as per recipe, in a cast iron pan, transferred to an oven dish, then laid the fish, cream and panko mix on top. Into the oven to bake.
This looks and sounds delicious
Question please. What pan did you use
Wow! I never thought fish, cream and potatoes would be so good together. I used cod, don’t like leeks so I used shallots instead, I had mushroom stock, didn’t have vegetable stock. The whole thing turned out awesome!!! The topping really made it crispy !!!! Loved it!!