Irish Fish Pie

1 1/2 lb firm white fish fillets 
1 large leek, chopped
2 strips lemon rind
1/4 tsp ground nutmeg
8 peppercorns
2 bay leaves
6 parsley stalks
2 1/2 cups milk
1 oz butter
1 clove garlic, crushed
1 extra leek, chopped
1/2 cup spring onions, chopped
2 tbsp plain flour
extra milk or cream
2 lb potatoes, cooked and mashed
ground pepper
1 tsp paprika (optional)

Preheat oven to 400F

Place fish fillets in a pan, add leek, lemon rind, nutmeg, peppercorns, bay leaves and parsley stalks. Pour in milk and simmer uncovered over a low heat for about 15 minutes or until fish is cooked.   Carefully remove fish fillets, strain off the liquid and reserve for sauce.  
Melt butter in a pan, add garlic, leeks and spring onions. Cook over a low heat for 7 minutes or until leeks soften. Remove half the mixture and reserve.

To make the sauce:
Sprinkle flour over remaining mixture in pan and blend until smooth. Measure the reserved poaching milk and make up to 1½ cups with extra milk or cream. Add to blended flour in pan, stir until mixture comes to the boil and thickens. Cook for 1 minute longer.

Cut fish into chunky pieces and fold gently through the sauce. Add reserved leek and spring onion mixture to mashed potatoes. Season both sauce and potato mixture with pepper.   Pour fish sauce into greased shallow casserole dish and top with mashed potatoes, using a fork to make a pattern. Sprinkle with paprika.   Bake at 400F for 20 minutes or until topping is brown.