Poached Fish with Spinach in Chilli-Tomato Sauce
Peer reviewed by UK recipe editorsAuthored by UK recipe editorsOriginally published 16 Jan 2026
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This poached fish with spinach in chilli-tomato sauce is a vibrant, Mediterranean-inspired dish that brings together delicate white fish and a robust, spicy base. The combination of fennel and red chilli adds a sophisticated depth of flavour, while the cherry tomatoes burst during simmering to create a naturally sweet sauce. It is a light yet deeply satisfying meal that celebrates fresh ingredients and simple cooking techniques.
As a diabetes-friendly main course, this recipe is naturally low in carbohydrates and packed with lean protein. Using white fish such as cod or hake ensures a tender texture that pairs perfectly with the salty olives and iron-rich baby spinach. Serve it alongside a generous portion of steamed seasonal greens for a nutritious, heart-healthy dinner that the whole family will enjoy.
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Ingredients for Poached Fish with Spinach in Chilli-Tomato Sauce
Olive oil
1 red onion, peeled and finely sliced
1 bulb of fennel, finely sliced
1 fresh red chilli, finely sliced (deseeded for less heat, if you like)
475ml tomato purée from fresh or canned tomatoes
2 handfuls (approx. 170g ) of cherry tomatoes, cut in half
Sea salt and freshly ground pepper
4 (140g) white fish fillets, such as cod, hake, or sea bass, skinned and pin-boned
120ml black or green olives, pitted
A handful of baby spinach
2 tablespoons finely chopped flat-leaf parsley
1 small clove of garlic, peeled and finely chopped or grated
Zest of 1 lemon, plus a squeeze of juice
How to make Poached Fish with Spinach in Chilli-Tomato Sauce
Put 1 tablespoon of olive oil into a pan on medium heat and sauté the onion, fennel and chilli for 2 to 3 minutes, to soften. Add the tomato purée and cherry tomatoes. Simmer for a further 4 to 5 minutes. Season to taste with a little salt and pepper.
Arrange the fish fillets in the pan, on top of the tomato sauce. Cover with a lid and simmer for 8 to 10 minutes, or until the fish is cooked and starting to flake. Just before serving, carefully stir in the olives and baby spinach and heat for a further minute.
Meanwhile combine the parsley, garlic, lemon zest, and juice in a bowl.
To serve, arrange the fish fillets on plates and spoon over the tomato sauce. Sprinkle with the herby topping, and add a squeeze of lemon juice to finish.
Enjoy this with some additional steamed greens.
Disclaimer
While every effort has been made to ensure the information is accurate and up to date, individual needs may vary and dietary requirements can differ based on personal health conditions. Always check food labels and allergen information before preparing or consuming any recipe. If you have specific health concerns, allergies, intolerances, or are following a medically prescribed diet, seek advice from your GP, pharmacist, or a registered dietitian before making significant changes to your diet or lifestyle.
Article history
The information on this page is peer reviewed by qualified clinicians.
16 Jan 2026 | Originally published
Authored by:
UK recipe editors
Peer reviewed by
UK recipe editors

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