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Cod with Potatoes and Preserved Lemon Relish

Peer reviewed by UK recipe editorsAuthored by UK recipe editorsOriginally published 16 Jan 2026

Meets Patient’s editorial guidelines

This elegant cod with potatoes and preserved lemon relish is a wonderful choice for a light yet comforting dairy-free dinner. By poaching the white fish in a fragrant milk infused with lemongrass, thyme and garlic, the cod remains incredibly succulent while absorbing subtle, aromatic notes. The use of olive oil instead of butter in the mash ensures a silky texture that remains light, making it a healthy alternative to traditional mashed potato dishes.

Deeply savoury and bright, the relish features hot smoked Spanish paprika and zesty preserved lemons, providing a beautiful contrast to the delicate fish. This recipe is perfect for those seeking a nutritious, high-protein meal that doesn't compromise on bold, Mediterranean-inspired flavours. Serve it as a centrepiece for a weekend lunch or a refined midweek supper.

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Ingredients for Cod with Potatoes and Preserved Lemon Relish

  • 1/2 medium onion, unpeeled, halved

  • 1/2 head garlic (halved crosswise)

  • 1 lemongrass stalk, trimmed, tough outer layers removed, finely chopped

  • 4 sprigs thyme

  • 1 tablespoon black peppercorns

  • 950ml low-fat milk

  • 575g Yukon Gold potatoes (about 4 large), scrubbed

  • Flaky grey sea salt or kosher salt

  • 60ml plus 45ml olive oil

  • 675g skinless cod fillet, cut into 2" pieces

  • 1/2 preserved lemon, finely chopped

  • 1/2 cup finely chopped chives (from about 1 large bunch)

  • 2 tablespoons fresh lemon juice

  • 1 tablespoon hot smoked Spanish paprika

How to make Cod with Potatoes and Preserved Lemon Relish

Bring onion, garlic, lemongrass, thyme, peppercorns, and milk to a boil in a large saucepan. Reduce heat to low and simmer 20 minutes. Strain infused milk into a medium saucepan. Discard solids.

Meanwhile, cook potatoes in a large pot of boiling salted water until tender, 25–30 minutes. Drain, then peel potatoes and coarsely mash in a large bowl with 60ml oil; season with salt.

Bring infused milk just to a boil. Add cod, reduce heat, and simmer until flesh begins to flake and is cooked through, about 5 minutes. Remove cod with a slotted spoon and transfer to a plate.

Combine preserved lemon, chives, lemon juice, paprika, and remaining 3 tablespoons oil in a small bowl; season relish with salt.

Mix 60ml infused milk into potatoes. Place cod over potatoes; spoon relish over.

DO AHEAD: Relish can be made 2 days ahead. Cover and chill.

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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