Cut the potatoes into chunks and cook in a saucepan of lightly salted water for 15 minutes, or
until tender. Drain well. Mash in the pan until smooth. Set over a low heat and beat in the milk,
butter, and salt and pepper.
Place the haddock fillets in a roasting tin and brush the fish with the oil. Sprinkle the garlic
on top, add salt and pepper to taste, then spread with the mashed potatoes. Roast in a preheated
oven, 230ºC / 450ºF / Gas Mark 8, for 8-10 minutes, or until the fish is just tender.
Meanwhile, preheat the grill. Transfer the fish to the grill and cook for about 2 minutes, or
until golden brown. Sprinkle with the chopped parsley and serve immediately.