Grill the cod for 4 minutes, turn the fish over, the brush with melted butter and cook for a further 4-5 minutes, or until the fish flakes easily.

Preheat the grill. Season the cod. Melt 25g of the butter, then brush some over one side of each piece of cod.

Meanwhile, heat the remaining butter, then add the vinegar followed by the capers and stir well.

Pour the vinegar, butter and capers over the fish, sprinkle with parsley and garnish with tarragon sprigs.