Slow roasted haddock or cod fillet means the fish is baked in the oven at a very low temperature. It means perfect baked fish every time. It means never overcooking. It means easy. It means healthy. Need I say more?
Low temperature cooking
Cooking food sous-vide is an example of low temperature cooking: food is sealed in a vacuum bag then lowered into a water bath kept at steady, low temperature. That signals fine restaurant dining or super expensive equipment, but so called ‘reverse seared’ steaks and joints are gaining popularity at home.
Low temperature roasting gives very similar results to sous-vide cooking, without the fuss of vacuum bags and water baths. Blast the meat for the Maillard effect before or after cooking it very gently, at oven temperature between 80C/176F and 125C/257F.
A good electric oven and a digital probe are required there, to maintain steady temperature and to check whether the food is cooked. That method ensures wonderful evenness of cooking throughout the meat joint, and perfect pinkness in the case of beef.
But even those of you familiar with this method might be surprised seeing fish feature in a low temp recipe. I hope to convince you that if restaurants can cook fish sous-vide, you can achieve a similar result in your home oven.
And they certainly do – this recipe is inspired by a restaurant meal where I was served the most unbelievably flaky, slimy and wet piece of cod. It was perfect: having just crossed the border between translucent and opaque, and tasted wonderful.
Slimy fish, perfect fish
By way of explanation, ‘slimy’ is in my view the best complement you can pay a cooked piece of fish. Fighting the hateful word ‘moist’, I aim to describe tasty meat as juicy but it won’t happily apply to fish.
Slimy in my books means that the fish flakes easily, looks like it’s dripping with moisture but it isn’t, slips into the mouth like it was lightly oiled and has not a touch of dryness or stringiness. ‘Slimy’ nails the experience.
How to cook fish well?
We all know (at least those of us who do know a thing or two about fish) that stringy, overcooked and dry are the three damning words when combined with fish.
Deep frying seals it in the horribly unhealthy but disgustingly tasty cocoon of batter. Pan-frying is fine for cooking tuna or thin fillets like sea bass, but it won’t quite cut it with a thick salmon fillets when you want it cooked through. Grilling can be a hit and miss, roasting is sensible and what works even better is low temperature roasting.
The only potential issue is that the fish will not be piping hot, having spent its time in nearly ambient temperature. That can be fixed by searing it after it’s cooked, but risking the fillet falling to bits a little.
I think that if you serve it with the sauce piping hot, on a properly preheated plate it will be absolutely fine.
How to cook low temperature haddock
I prefer to sear the fish before roasting, just so it looks more appetising, rather than for temperature or cookedness.
The oven should be set to about 80C/180F and you can also use a warming drawer if you have one, set to cooking function: they usually go up to 80C tops.
The roasting takes about forty-five minutes, for reasonably thick haddock loin fillets. You can measure the internal temperature with a digital probe: when it reaches 50-55C/122-131F, it’s done.
If you haven’t got a probe, prod the flesh with a fork to see if it flakes and is almost opaque inside.
Saffron sauce is a delight
It is a simple, roux-based sauce flavoured with saffron steeped in warm white wine.
Make the roux by whisking flour into foaming butter and cook stirring for a couple of minutes. Some mustard powder goes in (with a pinch of nutmeg if you like), then wine with the saffron and some fish or vegetable stock needs to be slowly poured in, while the sauce is stirred all the time.
Add salt and pepper to taste, cook it down to the desired thickness and it’s done.
Place the fish on very well warmed plates and spoon sauce whilst it’s bubbling, as pointed above. This dish is lovely with simple green vegetables on the side.
More haddock recipes
Oven baked haddock goujons in crispy panko breadcrumbs, served with tzatziki, Greek cucumber and herb yoghurt sauce.
Miso marinated haddock seared and baked to a succulent, golden beauty. Inspired by Nobu black cod, it is truly an outstanding fish dish.
Fish with mushroom gratin: haddock, turbot or sole fillets baked au gratin, covered with delicious mushroom sauce topped with crisp breadcrumbs.
More low temperature roasting recipes
Slow roasted salmon with dill sauce, baked at 100C/200F. Salmon roasted in very low oven, at 100C, takes about 45 minutes to cook. Salmon cooked this way is moist and succulent, tastier than poached, and served with the easiest dill sauce that goes with any fish.
Pork loin roasted at low temperature, served with blueberry sauce. Low temperature roasting makes for fantastic succulent meat and the blueberry sauce is the best for pork.
Roast sirloin of beef cooked at low temperature produces as fantastic results as sous-vide cooking. The caveat: best if you own a digital meat probe of some kind.