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!
I was a little hesitant, since I’m not usually a huge fan of fish, but tried this recipe and loved it! Beautiful flavors that all work really well together.
Can you tell me what size pan you used? Thank you.
Hi Steve. Point 5 in the instructions mentions a large oven-proof skillet (30cm/12″)
Hope that helps 🙂
As so many others have already said – super easy and absolutely delicious. The leek/cream/potato/wine combination is absolutely luscious and goes wonderfully with the juicy fish and crispy topping. I’m sure it’s worth making if you don’t have leeks but if you can use leeks they definitely take it up a notch!
Oh joyous joy! Superb recipe absolutely devoured by all. Only little tweak was a touch of tarragon. My teens have noe taken to asking me daily “Which Nagi recipe tonight, Mum?” 😀
Hi Nagi. I have just bought your recipe book Dinner. For me and my two daughters. We. are all thrilled. I love cookbooks, but this is my favourite. Cannot believe how reasonable the cost was. It is worth much more. Thankyou.
Best fish meal ever! Easy, tasty, quick. Even the kids love it..yes it’s ‘chicken’!!
Was absolutely beautiful the most beautiful recipe that was unexpected and I loved everything about this..did the veg stick as I don’t,like the wine flavour added loads of pepper it was to die for I called it sex on a plate thanks so much
O…M…G ❤️
Love this recipe, and my husband is a huge fan too. Perfect oven baked yumminess for these chilly NZ winter nights. Another winner Nagi!
Ooops, forgot the stars…
This was absolutely sensational. My husband said it was the best fish meal he has ever had!
Made this last night – just as written – fantastic! Seriously – PERFECT barramundi and delicious crunchy topping and leek & potato base. Will go into regular rotation – thank you!
Same here in Rheims: my spouse and our son just grabbed the recipe, did it whilst I was comfortably working: just perfect
Nagi ~ another 5 ⭐️ recipe. I’ve made this twice, both times with salmon. Super easy week night dinner. I added spinach to make it a one pot meal.
Oops! Five stars, of course!
Nagi, another absolute winner! I was caught out without leek, cream and white wine but wanted to make this for dinner tonight. I had 4 beautiful pieces of John Dory that hubby had caught. I subbed a chopped onion and thickly sliced zucchini for the leek. Used a lovely dry rosé instead of white wine. And made up an extra thick mix of dry milk powder and water plus a teaspoon of cornflour. Followed method to the letter. Yummo! Worked perfectly and hubby has asked for this to be repeated regularly. Thank you for another delicious recipe which I’ll make again as written 😉
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.