Smoked cod pie

Preheat oven to 180C. Put smoked cod in saucepan with water to cover,bring to boil and boil till tender. Remove from heat and drain. Cool for a few minutes then peel skin and discard,flake the flesh,put aside. In frypan,put onion and celery and fry slowly till softened,add corn and cook for further two minutes. Add fish,cream of celery soup and 1 cup milk,stir and bring to simmer, add saffron,salt and pepper. Make a roux by melting 40 grams butter in small saucepan,add 2 tablespoons plain flour and stir continually for 1 minute, slowly add 2 cups milk, a little at a time while continuing to stir, once all milk is added turn up heat and bring to boil. Take off heat then add to fish mixture,bring mix bake on hot plate and simmer till thickened. Pour mix into greased casserole dish and set aside. Put potatoes in saucepan with water to cover,bring to boil. When boiling ,do not put lid on saucepan,continue to boil until potatoes are tender. Remove from stove and mash. Add extra 20 grams of butter and milk to form a smooth mash. Put mashed potato mixture carefully on top of fish mixture ,put in preheated oven for 30 minutes or until potato has started to turn golden. Remove from oven,cool slightly and serve