Luxe Seafood Pie with Rosti Topping

The original recipe called for individual pies…which would be great except I didn't have 6 - 2 cup oven proof dishes so I made 1 pie and it worked just fine.  I just used my cast iron frying pan.  I like the Arctic Char, Trout and Lobster are all sustainably caught species and the combination of the three is rich and delicious.  From Food and Drink Autumn 2011.

FILLING
1 medium onion
2 cups whole milk (I used 1% and it was still rich)
1/2 tsp black peppercorns
2 bay leaves
Pinch freshly grated nutmeg
500g Arctic char or pickerel fillets
1/4 cup unsalted butter
2 cloves garlic, minced
1/2 cup dry white wine
250 g smoked trout or mackerel fillets
250 g cooked, shelled lobster meat
1/3 cup all purpose flour
Pinch cayenne
1/2 cup whipping cream
1 cup frozen peas, thawed and drained
1/4 cup each finely chopped parsley and chives
1 tbsp drained capers
4 small cornichons, drained and finely chopped
1 tsp Worcestershire sauce
Kosher salt and freshly ground pepper

ROSTI TOPPING

4 yukon gold potatoes, each 3 inches, peeled
1/4 cup unsalted butter; melted
2 tbsp finely chopped parsley
1/4 tsp each kosher salt and freshly ground black pepper

1. For filling, cut a thick slice from onion and finely chop remainder.  In a medium saucepan, combine onion slice, milk, peppercorns, bay leaves and nutmeg.  Bring milk to a simmer over medium high heat.
2. Cut Arctic char fillets into large pieces sized to fit the saucepan, and add to simmering milk.  Reduce heat to low and poach, covered, 5 to 10 minutes or until fish is opaque throughout.  Remove from heat and set aside.
3. In a small skillet, heat 1 tbsp butter over medium heat.  Add chopped onion and cook, stirring often for 5 to 7 minutes or until softened but not browned.  Add garlic and cook, stirring for 30 seconds or until fragrant.  Add wine and bring to a boil.  Simmer for 1 to 2 minutes of until wine has reduced by half.  Remove from the heat and set aside.
4. Strain Arctic char, reserving milk but discarding flavourings.  Flake Arctic char into bite size pieces, discarding any skin and bones.  Put in a medium bowl.  Flake trout into bite-size pieces, discarding any skin and bones.  Cut lobster into bite size pieces.  Add trout and lobster to Arctic char.
5. In a large saucepan, heat remaining butter oer medium heat.  Add flour and cayenne and cook, stirring constantly, for 1 to 2 minutes or until the flour and butter roux looks dry and is fragrant (do not brown). Gradually whisk in reserved milk, then cream.  Cook for about 2 minutes, whisking constantly, until sauce thickens and is smooth.  Remove from heat.
6. Stir onion mixture into sauce, then add fish mixture, peas, parsley, chives, capers, cornichons and Worcestershire sauce.  Stir gently.  Season with salt, pepper and more cayenne if necessary.  Divide mixture among six 2 cup individual baking dishes.  If you're not completing the pies immediately, cover and refrigerate them until ready to proceed, removing them from the refrigerator about 30 minutes before adding the topping.
7. For rosti topping, preheat oven to 400F.
8. Put potatoes in a large saucepan and add enough cold water to cover them.  Bring to a boil over high heat.  Reduce heat to medium-low and simmer, covered for 10 minutes. Drain well and set aside until cool enough to handle.
9. Using the large holes on a box grater, grate potatoes into a large bowl.  Add butter, parsley, salt and pepper and mix with a fork until well combined.
10. Spoon potato mixture on top of seafood filling to cover it completely, dividing evenly.  Put dishes on a large baking sheet.  Bake for about 30 minutes or until potato is starting to brown and filling is bubbling.

Serves 6