Peel and finely chop the onion.

Wash and finely slice the leek.

In a large pan, slowly fry the onion and leek with olive oil for 5 minutes until soft and tender.

Halve the courgettes (zucchini) lengthways.

Remove and discard the fluffy core from the courgettes with a teaspoon.

Grate the remaining courgette into the pan.

Peel the potatoes.

Chop the potatoes into rough 2cm/1-inch dice.

Add the potatoes to the pan.

Stir everything well.

Add the anchovies.

Turn the heat up.

Add the white wine.

Cook down the wine by half.

Add the milk and stock.

Bring to the boil.

Simmer for half an hour until the potatoes are tender.

Skin and pinbone the cod fillet.

Add the cod to the pan.

Simmer for a further 15 minutes until the flesh flakes away.

Season carefully to taste with salt and pepper.

Roughly chop the parsley.

Finely slice the spring onions (scallions).

Divide the stew between bowls.

Garnish with parsley and spring onion dressed with olive oil and lemon juice.