Pan-Seared Mackerel with Tangy Rhubarb Chutney

Combine the diced red onion, grated ginger, mustard seeds, sugar, and vinegar in a heavy-bottomed saucepan.

Bring the mixture to a simmer over medium heat and cook for 5 minutes until the onion softens.

Add the chopped rhubarb. Continue to simmer gently for 10-15 minutes until the rhubarb breaks down and the mixture thickens to a jam-like consistency. Remove from heat and let cool.

Pat the mackerel fillets thoroughly dry with paper towels. Using a sharp knife, make 3 shallow diagonal scores in the skin of each fillet to prevent curling.

Season the fish generously with salt and pepper. Heat olive oil in a large non-stick frying pan over medium-high heat until shimmering.

Place fillets skin-side down in the pan. Press down gently with a spatula for 10 seconds to ensure even contact. Cook without moving for 3-4 minutes until the skin is golden and crispy, and the flesh is opaque 2/3 of the way up.

Flip the fillets and cook for 30-60 seconds on the flesh side until just cooked through. The internal temperature should reach approx 60°C/140°F.

In a mixing bowl, toss watercress and sliced radishes with lemon juice and extra virgin olive oil. Season lightly with salt.

Plate the salad, place a mackerel fillet alongside (skin-side up to maintain crispiness), and spoon a generous amount of rhubarb chutney on the side.