First place the milk into a large saucepan and add the onion and bay leaves. Heat the milk until it’s just about to boil, take off the heat and leave for half an hour to let the onion and bay leaves infuse.
Place the infused milk back onto the hob, season with salt and pepper and bring up to a gentle simmer. Place the fish fillets in the pan, cover with the lid and simmer for two minutes.
Remove from the heat and set aside to cool for five minutes.
Use a slotted spoon to transfer the cooked pieces of fish into the ovenproof dish. Remove the bay leaf and onion from the milk and reserve for later.
Scatter the prawns over the fish. Cover and set aside.
Fill a medium saucepan with cold water and bring to the boil, reduce the heat to a simmer.
Place the quails’ eggs in the saucepan and simmer for 3 minutes exactly.
While the eggs are cooking fill a medium bowl with ice and fill with water.
Drain the eggs and place in the bowl of iced water. Leave until the eggs are cold (5 or so minutes), then peel them and place over the fish in the ovenproof dish.
Cover the dish with clingfilm while you make the sauce.
Melt the butter in the other medium saucepan and stir in the flour. Cook for a minute or two until the flour has cooked through, and then gradually add the infused milk and continually stir until the sauce is thick.
Add the grated cheese and continue stirring until melted. Season with a little salt and a few grinds of black pepper.
Take off the heat and add the wine and cream and stir in thoroughly.
Remove the clingfilm from the ovenproof dish and scatter over the chopped dill.
Pour over the sauce and gently stir in so it coats the fish, prawns and eggs, and the dill is evenly incorporated throughout. Cover with clingfilm and set aside while you make the potato topping.
Place the potatoes in a large pan of cold water, bring to the boil and cook for 15 to 20 minutes or until the potatoes are tender.
Drain the potatoes in the colander and squeeze the potatoes through a potato ricer into the saucepan. Add the butter and enough milk to make a smooth but quite stiff mashed potato. If you don’t have a potato ricer then just drain the potatoes through the colander, return to the saucepan and mash with a potato masher adding the butter and milk half-way through the mashing.
Preheat the oven to 200C/400F/Gas 6.
Remove the clingfilm from the ovenproof dish and carefully dollop spoonsful of the mashed potato over the top.
Use a fork to gently spread the potato evenly over the pie using the prongs to make grooves in the top of the potato.
Sprinkle the top with the grated cheddar, place in the preheated oven and bake for 45 minutes or until the top is golden brown and the filling is bubbling.
Serve immediately with garden peas or petit pois.
