Oven-Baked Cod with Sweet Onion Sauce

Cod is something that most of us Brits only ever encounter encased in batter. Not that there’s anything wrong with that, I hasten to add. I’m a huge fan of battering pretty much anything – and I’m not even Scottish! But even without the crunchy coating it’s a lovely part of any meal. Cod, like a lot of white fish, has a delicate, almost sweet flavour but enough presence to hold its own against some fairly robust sauces.

As here, where I’ve served oven-baked cod fillets alongside a rich, sweet onion sauce. The onion in the sauce retains a lot of its strong savoury flavour, but the slow cooking time makes it a lot more mellow. There’s no harsh onion flavour here. As the onions are browned, but not caramelised, the sauce is sweet but not too sweet. No doubt helped by the fact there’s no added sugar.

Served here with my Warm Garlic & Spinach Potato Salad it makes for a lovely evening meal that’s absolutely packed with flavour.

Oven-Baked Cod with Sweet Onion Sauce

Cod has a wonderful, delicate taste but it's robust enough to stand its ground against some pretty punchy flavours, such as this moreish sweet onion sauce. Trust me, you'll be going back for more!
Prep Time10 mins
Cook Time30 mins
Total Time40 mins
Course: Main Course
Cuisine: Fish
Servings: 2
Calories: 326kcal


For the Sweet Onion Sauce

  • 40 g Butter
  • 1 Onion peeled and chopped
  • 2 cloves Garlic peeled and crushed
  • 200 ml Good Quality Vegetable Stock
  • 1 tbsp Double Cream
  • 2 tbsp Fresh Parsley finely chopped

For the Cod

  • 2 Cod Fillets approx 120g each


  • Preheat the oven to 160°C.
  • Melt the butter in a pan over a medium-low heat. Add the onion and cook for 15-20 minutes until softened. Stir frequently and take care to make sure that the onion browns slightly without burning.
  • Add the garlic to the pan then cook for a further minute or so until fragrant.
  • Pour in the vegetable stock, then turn up the heat and bring to the boil. Loosely cover, then simmer for around 10 minutes until the liquid has reduced by half.
  • Press the mixture through a fine mesh sieve with a wooden spoon, to create a thick sauce. Return to the pan, then add the double cream and parsley. Keep warm.
  • Meanwhile, place the cod fillets onto tin foil, or parchment paper, then loosely form into parcels. Place on a baking sheet and bake in the oven for 15-18 minutes, until cooked through and tender.
  • Serve the cod on top of a generous pool of the sweet onion sauce, and enjoy.


Estimated Values per Serving
of which Saturates13g
of which Sugars2g
Note: Nutritional information shown is per serving of the above recipe. Any side dishes or garnishes shown in photos are not included in these values, unless they are specifically listed as part of the recipe.

Scott Silverthorn

Hi, I’m Scott. I love cooking food and I love eating it - both useful credentials for writing a food blog! I get a lot of joy from sharing my passion with my friends and family, so here's hoping you enjoy it too.

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