Friday night fish pie

Name: Friday night fish pie
Prep time: 40 min
Cook time: 55 min
Total time: 1 h 35 min
Cuisine: British
Ingredients: 1½kg potato, chopped into chunks; 50g butter; 1½l full-fat milk; 800g skinless white fish; 600g skinless smoked haddock fillet; 1 onion, quartered; 2 bay leaves; 140g butter; 140g plain flour; nutmeg, to season; small bunch parsley, leaves only, finely chopped; 200g cooked, peeled prawns; 6 eggs, hard-boiled and quartered (just 3 eggs if you are freezing one of the pies, as the eggs can't be frozen)