Butter a casserole or any baking dish generously .Line it with a layer of sliced onions ,next spread it with a layer of sliced potatoes .Next if you prefer add in the fish fillet. Traditional method calls for the fish layer too. But I skipped it.
Now pour in the heavy cream .Sprinkle in the breadcrumbs and some chilli flakes and salt .finally add in the cheese and butter cubes randomly.
Preheat the oven at 220 Deg C for 10 mins and bake at 200 Deg C for about 40-45 mins are until the top brown and potatoes soften and cream has reduced.
Notes
Serve as a breakfast or as a snack.
Usually the dish is prepared with any sea food as it makes for the Christmas table, but I skipped for my convince. For veg version use mushroom as another layer if you prefer.