500g/1lb 2oz Jersey Royal potatoes, scrubbed and halved
200g/7oz summer herbs, such as chervil, curly parsley or chives, roughly chopped
½ onion, finely chopped
400g/14oz baby spinach
150g/5½oz plain flour
salt and freshly ground black pepper
150g/5½oz panko breadcrumbs
salt
4 tbsp vegetable oil
2 tbsp vegetable oil
50g/1¾oz unsalted butter
50g/1¾oz butter
150ml/5fl oz double cream
2 free-range eggs, at room temperature
250ml/9fl oz milk
2 cod fillets, skin on and pin-boned
1 free-range egg, beaten