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Cod Mornay with Spinach

Cod mornay is a classic French dish that consists of fish baked in a cheese sauce, I like to add spinach, wholegrain mustard & breadcrumbs.

This dish may sound intimidating, but it is three easy processes, and then all you have to do is stick it all together and throw it in the oven!

Baked Cod mornay with a breadcrumb topping served with potatoes and broccoli.

Classic Fish Mornay

I adore cooking with fish and it has featured much more regularly since our return to the UK.

This delicious cod mornay recipe is French in origin, just like my pan-fried lemon sole meuniere recipe, but it feels very British to me in so many ways.

It features cod or any other white fish cooked in a cheesy sauce with a hint of mustard, grainy mustard n this particular case.

Cod is a glorious treat and I use it in dishes as diverse as my simple pan-fried cod with chorizo recipe to my Thai green fish curry and my fish burger to baked cod in breadcrumbs.

The mornay sauce is thought to date back to the 16th century, which predates the bechamel sauce that it is obviously based on.

But it is essentially a white sauce, the same base as I use for my parsley sauce, with cheese and mustard.

It’s all then layered up, topped with golden breadcrumbs and baked until the fish is perfectly cooked.

This recipe is very much a “brother from another mother” dish to my smoked haddock gratin, which will lead you nicely onto my smoked haddock rarebit recipe…. happy cooking!

Overhead cod mornay with a breadcrumb topping in a baking dish.

Frequently Asked Questions

Can I use different types of fish?

Yes, it is good with any “meaty” firm fleshed white fish. Hake or haddock are both good, although the boldly flavoured sauce leans me towards choosing cheaper white fish.

Pollock and coley (my choice for my masala fish recipe) are perfect in this dish and less than half of the price of cod.

Can I use a fillet of fish rather than a loin?

Yes, the fillet tends to be a lot thinner than the loin and less even in thickness. This means it takes less time to cook, maybe as little as 15 minutes.

The trade-off is that it is much easier to overcook the fillet than it is the loin.

Do I have to use the spinach?

Nope, you can skip it if you like.

The reason I use it is two-fold, the first is that it tastes superb and second it prevents the cod sticking to the baking dish.

Can I use a different type of cheese?

Yes, a traditional Mornay sauce would have been made with something like a Gruyere cheese.

Its sweet and nutty flavour is superb in this recipe, another cheese that works particularly well is comte. parmesan is very popular although it is not my favourite in this recipe.

Cod mornay with a cheesy sauce and breadcrumb topping served with potatoes and broccoli.

Serving Suggestions

My cod mornay recipe is pictured here served with Parmentier potatoes and some roasted tenderstem broccoli.

Mash is an incredibly popular side dish with this recipe, with mashed potato being the favourite.

However, I think that celeriac mash is a better option as it is a little lighter and provides a wonderful complimentary flavour.

Alternative options for greens include buttered cabbage or something like braised cavolo nero.

If you wanted something altogether lighter how about my warm samphire salad, it is glorious with fish!

Cod mornay with a breadcrumb topping in a baking dish.

Equipment Used

I only mention brands of equipment if I think they make a material difference to a recipe. If you have any questions feel free to ask them in the comments section below the recipe.

  • Stovetop.
  • Oven.
  • 15cm or 6″ saucepan.
  • 20cm or 8″ saucepan.
  • 15-20cm or 6-8″ frying pan.
  • 25x17x5cm or 10x7x2″ baking dish.
  • Weighing scales and or measuring cups and spoons.
  • Mixing spoons.
  • Sieve.
  • Cheese grater.
Baked cod Mornay with spinach and cheese sauce served with potatoes and broccoli.
Yield: 2 Servings

Cod Mornay Recipe

Cook Time: 1 hour
Total Time: 1 hour

Cod mornay is a much-maligned dish thanks to the ghastly "TV Dinner" versions, but this classic French dish of fish baked in a bechamel-based cheese sauce is simply stunning!


  • 2 (∼350g Total) Boneless Skinless Cod Loin Pieces
  • ¼ Tsp Salt

For the Breadcrumbs.

  • 1 Tbsp Rapeseed (canola) Oil
  • 25g (⅓ Cup) Dried Breadcrumbs

For the Spinach:

  • 15g (1 Tbsp) Butter
  • 200g (2½-3 Packed Cups) Baby Spinach
  • ¼ Tsp Salt

For the Mornay Sauce:

  • 30g (2 Tbsp) Butter
  • 30g (¼ Cup) Flour
  • 300g (1¼ Cup) Full Fat Milk
  • ¼ Tsp Salt
  • ¼ Tsp White Pepper
  • 50g (½ Cup) Grated Cheddar Cheese
  • 1 Tbsp Wholegrain Mustard


  1. Heat a small 15-20cm (6-8") frying pan over a medium-high heat and when it is hot add the rapeseed oil for the breadcrumbs.
  2. Pour in the dried breadcrumbs and cook until golden, this will take 5-8 minutes, then transfer to some kitchen paper to absorb any excess oil. Then set aside.
  3. Heat a 20cm or 8" saucepan over a medium heat and melt the butter for the spinach.
  4. Throw in the spinach and salt and stir continuously until the spinach has wilted, this will take 5 or 6 minutes. Then transfer to a sieve and allow to drain whilst you cook the mornay sauce.
  5. Heat a 15cm or 6" saucepan over a medium-low heat and add the butter for the mornay sauce.
  6. Add the flour and stir for 2-3 minutes until the flour cooks out and forms thick "paste" with the butter.
  7. Add the milk little by little until you have a smooth and lump-free white sauce, this will take 8-10 minutes.
  8. Turn the heat down to very low and add the cheese and stir until the cheese has melted and you have a very smooth sauce.
  9. Add the mustard, salt and white pepper, stir again and set aside for a moment.
  10. Squeeze out any moisture from the spinach and arrange two piles about the same size as the cod in a 25x17x5cm (10x7x2″) baking dish.
  11. Season the cod with a little salt and place it on top of the spinach.
  12. Pour over the cheese sauce, then sprinkle the breadcrumbs, I prefer to do this just over the fish.
  13. Transfer to the oven and cook at 180°C or 350°F for 25-30 minutes (less if you are using cod fillet). You want an internal temperature in the centre of the fish of around 60-63°C (140-145°F). It is best to allow the dish to rest for 2-3 minutes before plating.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 654Total Fat: 33gSaturated Fat: 19gTrans Fat: 1gUnsaturated Fat: 11gCholesterol: 181mgSodium: 1642mgCarbohydrates: 33gFiber: 4gSugar: 9gProtein: 57g

Calorific details are provided by a third-party application and are to be used as indicative figures only.

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