Smoked Haddock Gratin

Preheat the oven to 200°C.
Prepare the fish: Poach the smoked haddock gently in the milk for 5–6 minutes, or until just cooked through. Remove the fish and set aside, reserving the milk.
Cook the leeks: Slice the leek finely and sauté in a little butter until soft and translucent.
Make the cheese sauce: In a saucepan, melt the remaining butter, then stir in the flour to form a roux. Gradually whisk in the reserved warm milk to make a smooth sauce. Stir in half of the Arla Cheese until melted and creamy. Season to taste. Add sautéed leeks and flakey poached smoked haddock.
Assemble the gratin: In a lightly buttered ovenproof dish, pour haddock mixture in and top with sliced potatoes.
Finish with cheese: Sprinkle the remaining Arla Cheese over the surface for a golden, gratinated topping.
Bake: Place in the oven and cook for 35–40 minutes, or until the potatoes are tender and the top is bubbling and golden.
Serve hot, ideally with a crisp green salad or seasonal vegetables.