Poached Whole Arctic Char

Lay whole fish in poaching pan or large roasting pan. Cover with cold fish stock. Add remaining ingredients to immerse fish. Cover pan. Poach on stove top by bringing to a gentle simmer over medium high heat. Reduce to low heat and continue to simmer very gently for 10 to 12 minutes until the fish is firm to the touch and warm in the centre. Alternately cover the roasting pan with foil and poach in 350 degrees F oven until fish is firm to the touch and warm in the centre. Times will vary according to size of fish. Remove from stove top or oven and let cool to room temperature in poaching liquid. Remove fish from poaching liquid and set aside. Strain the poaching liquid, reserving about half a cup for sauce.

Puree arugula in food processor with a little water until leaves are pureed. Strain and discard solids. Puree strained arugula liquid with 3 tablespoons butter and chill for 1 hour. Combine 1 teaspoon of butter and shallots in a small saucepan. Sauté 2 to 3 minutes until shallots are soft. Add the poaching liquid and mustard and stir to combine. Simmer 5 to 7 minutes or until reduced by one quarter. Gradually add cold pieces of arugula butter while whisking to combine. Season to taste and serve warm over poached fish.