1 onion, finely sliced
400g/14oz potatoes, chopped
2 tbsp plain flour
salt and pepper
150驳/5陆辞锄 breadcrumbs (made from 4-5 slices of bread, broken into breadcrumbs and dried slightly)
1 tbsp olive oil
25g/1oz butter
100驳/3陆辞锄 cream cheese
1 egg, beaten
360g/12oz frozen white fish fillets (such as Coley or Pollock), defrosted, skin and bones removed
300g/10陆oz frozen peas