Poached Haddock with Mustard Sauce – 5:2 Diet Friendly Recipe

Introducing British Quark and a new 5:2 Diet Recipe:

Mea Culpa.  I am shallow and although I thought I’d have little interest in a ‘new dairy product from Lake District Dairies’, I did think that having my lunch cooked for me by the Fabulous Baker Brothers might be fun.  Which of course it was.  But, there was a more serious note, I also discovered a fabulous new ingredient that I suspect will become a staple in my fridge for 5:2 diet fast days.

Fabulous Baker Brothers

Now, where else would I get to see ‘flatbread tossing’ done with such style?

quark flatbreads

Of course we were there to learn about English quark – but we got to eat a lovely dish of Spicy Lamb with quark dressing and flatbreads.  Followed by Carrot Cake made with quark.  And, it was all VERY healthy.  And, we had the Fabulous Baker Brothers cooking it all for us!

Spiced lamb with quark and flatbreads

Once I’ve had a go at making these recipes I’ll post them up here, but for now I’ll simply share the infographic that we were given by Fiona Hunter – the nutritionist who was at the event to explain some of the health benefits of quark to us.

Quark Infographic

Now I have tried quark in cooking before but the only variety available was a bit too much like cottage cheese to work very well.  The newly launched Lake District Dairy Quark has fabulous health benefits but is also smooth – not unlike creme fraiche in texture but with a fraction of the calories (even of half fat creme fraiche).  And it DOES work well in recipes.  The advantage of the high protein content of quark is that it helps you feel full for longer – and all that in a very low calorie product.

To test it out I decided to try using some of my Haddock from DelishFish with a creamy mustard sauce.  It’s something I’ve attempted before with creme fraiche and low fat yoghurt, but never succeeded in making effectively (although it is fine with double cream!).   As someone said, you end up with a lumpy sauce if you use low fat products.  But this time it worked, as you can see from the photo. Not bad ehh?  I’m actually quite impressed myself that I’ve got that lovely glossy effect on the sauce.

Haddock with Mustard Sauce

This is one of those recipes that will work well whether or not you are on a 5-2 diet fast day.  Simply adjust the vegetables you serve (here, 100g of new potatoes and the same of peas).  And, it’s a great dish for this time of year when the weather seems to want to say ‘spring’ but it still feels chilly in the evenings.

5-2 Diet Poached Haddock with Mustard Sauce

Serves 1
Prep time 5 minutes
Cook time 15 minutes
Total time 20 minutes
Allergy Fish, Milk
Meal type Lunch, Main Dish
Misc Serve Hot


  • 1 piece Haddock Fillet (about 150g)
  • 1 tablespoon Quark
  • 1 teaspoon Mustard (adjust the quantity depending on the strength of your mustard!)
  • 10g Butter
  • 1 teaspoon Chopped Chives
  • 50ml Dry white wine
  • 150ml Milk (or enough to cover the fish fillet while poaching)
  • 1 handful Fresh Parsley (to garnish)


Step 1 put the milk into a pan large enough to hold the fish fillet. Bring to the boil
Step 2 Add the fish and season with salt and pepper. Bring back to a gentle simmer, then turn off the heat and cover. Allow to rest for 10-15 minutes so that the fish is fully cooked
Step 3 Meanwhile make the sauce by melting the butter in a small pan, adding the chives and cooking for just a minute, then adding the white wine. Reduce the mixture down by 2/3rds
Step 4 Take the liquid off the heat and stir through the mustard and quark. If you are not sure about the strength of your mustard, add half to start then adjust by taste.
Step 5 Carefully remove the fish from the poaching liquid and plate up, pour the sauce over and garnish with fresh parsley
Step 6 Serve with vegetables of your choice - here, new potatoes and peas.

I used butter in my version of this recipe which added about 70 calories!  but as a tablespoon of quark is around 15 calories, the rich creamy looking sauce is still quite low in calories – despite the butter and wine I added!  Mustard gives a lovely piquancy to the dish and works well with haddock.  You could use the same sauce with smoked haddock or even with cod or hake.

5-2 diet haddock with mustard sauce

Disclaimer:  I was sent samples of fish by DelishFish and provided with samples of Quark by the Lake District Dairy, but was under no obligation to review either product on London-Unattached

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  1. Pamela Morse says

    I wish we could buy quark..the Swiss have it everywhere. Nice way to use it in the sauce too. I like it straight up myself.

  2. Tracy Nixon says

    Mmmm I love anything with a mustard sauce! I love the stuff especially the whole grain French!

  3. says

    I love all your 5:2 diet recipes, such a good help when looking for something low cal. I’ve got some haddock from DelishFish, so this looks perfect for me to try out, I just hope it looks as good as yours does.

  4. lauren olds says

    i’ve only recently got into mustard. i might have to try a creamy mustard sauce some time. as this looks really nice!

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