Heat the oven to 200C fan 180C gas mark 6.
Put 1 kg potatoes patates , peeled and halved, in a saucepan and pour over enough water to cover them. Bring to the boil and then simmer until tender.
When cooked, drain thoroughly and mash with a splash of milk süt and a knob of butter tereyağı . Season with ground black pepper karabiber .
Put 25g butter tereyağı , 25g plain flour un and 4 finely sliced spring onions taze soğan in another pan and heat gently until the butter has melted, stirring regularly. Cook for 1 -2 mins.
Gradually whisk in 400ml milk using a balloon whisk if you have one. Bring to the boil, stirring to avoid any lumps and sticking at the bottom of the pan. Cook for 3 4 minutes until thickened.
Take off the heat and stir in 320g-400g mixed fish balık , 1 tsp Dijon or English mustard dijon veya İngiliz hardalı , handful of sweetcorn and handful. Spoon into an ovenproof dish or 6- 8 ramekins.
Spoon the potato on top and sprinkle with a handful of grated cheddar cheese kaşar peyniri .
Pop in the oven for 20-25 mins or until golden and bubbling at the edges. Alternatively, cover and freeze the pie or mini pies for another time.