Step 1

Preheat the oven to 350F

Step 2

Put the milk and bayleaf in a saucepan over medium heat. Cut the fish into 4 or 5 pieces and add to the milk along with 1/2 tsp salt. Bring to a gentle boil, then turn down the heat and simmer for a few minutes. Remove from the heat, cover, and set aside.

Step 3

In a large pot melt 2 tablespoons of the butter and saute the parsnips and leeks for about 10 minutes over medium heat until softened. Stir often and don't allow them to burn.

Step 4

Strain the fish and reserve the milk. Set both aside.

Step 5

Add the flour to the parsnips and leeks and cook, stirring, for a few minutes, and again, don't let it brown. Slowly pour in the strained milk, stirring constantly, until smooth. Continue heating until the mixture thickens and almost comes to a simmer.

Step 6

Add the fish to the pot, breaking it into large chunks as you add it. Season with salt and plenty of fresh cracked black pepper to taste. Stir in the frozen peas. Cover and set aside on the stove top to keep warm.

Step 7

Meanwhile cook the potatoes in plenty of salted water until completely soft. Drain them and whip with 2 tablespoons of the butter, the cheese, the butttermilk, and the horseradish. Season to taste with salt and pepper. Be sure to get out all lumps.

Step 8

Turn the fish mixture into your baking dish. Top with the mashed potatoes. You can pipe them on (see inspructions in the blog post) or just spoon them on. Melt the remaining 2 tablespoons of butter and gently dab over the mashed potatoes with a silicone brush. If you like you can brush again during cooking.

Step 9

Bake for 30-40 minutes until golden browned and bubbling.