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Slow-Roasted Arctic Char with Lemon-Mustard Seed Topping

This slow-roasted Arctic char with a lemon and mustard seed topping is a refined yet simple choice for a heart-healthy main course. By cooking the fish at a lower temperature, the delicate oils are preserved, resulting in a buttery, melt-in-the-mouth texture that pairs beautifully with the zesty, textured crust. The combination of crushed mustard seeds, fresh parsley, and dried tarragon provides a sophisticated depth of flavour without the need for excess salt or heavy animal fats.

As a wonderful alternative to salmon, Arctic char is rich in omega-3 fatty acids, making it a nutritious addition to your weekly menu. Serve these fillets alongside steamed seasonal greens or a crisp watercress salad for a light, balanced dinner. It is an ideal recipe for those seeking a high-protein meal that feels indulgent while remaining firmly within a healthy eating plan.

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Ingredients for Slow-Roasted Arctic Char with Lemon-Mustard Seed Topping

  • 1 teaspoon grated lemon zest

  • 1 tablespoon extra virgin olive oil

  • 1 1/2 tablespoons multigrain bread crumbs

  • 1 tablespoon finely chopped fresh flat-leaf parsley

  • 1/4 teaspoons dried tarragon

  • 2 teaspoons mustard seeds, crushed

  • 1 tablespoon white wine vinegar

  • 1 tablespoon fresh lemon juice

  • 2 teaspoons Dijon mustard

  • 1/8 teaspoons sugar substitute

  • Four 140g Arctic char fillets, skin on

  • Freshly ground pepper

How to make Slow-Roasted Arctic Char with Lemon-Mustard Seed Topping

  1. Preheat the oven to 121°C.

  2. In a bowl combine the zest, olive oil, bread crumbs, parsley, tarragon, mustard seeds, vinegar, lemon juice, mustard, and sugar substitute. Line a baking pan with parchment paper and place the fish in the pan, skin side down. Sprinkle with pepper.

Spread some of the lemon-herb mixture on each fillet.

  1. Bake the char for 30 to 35 minutes, depending on thickness, until the fish is almost completely opaque. Allow to rest for 5 minutes before serving.

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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