200g/7oz celeriac, peeled and cut into cubes, cooked until tender, drained
1 lemon, juice only, plus extra lemon wedges, to serve
200g/7oz new potatoes, cooked until tender, drained
½ onion, peeled, finely sliced
3 tbsp chopped fresh parsley leaves
1 fresh bay leaf
salt and freshly ground black pepper
25g/1oz flour
50²µ/1¾´Ç³ú flour
pinch freshly grated nutmeg
4 whole white peppercorns
1-2 tbsp vegetable oil
35²µ/1½´Ç³ú butter
75g/3oz butter
1 tbsp double cream
300ml/10½fl oz full-fat milk
4 x 175g/6oz cod fillets