Lemony cod and potato stew

Cook the finely chopped onion in about a quarter cup of olive oil in a shallow pot over medium heat until soft, without color, about 8 to 10 minutes.

Thinly slice the scallions down to the roots.

Put the slices in a bowl of cold water so the dirt sinks; lift them out into a strainer (do not pour over a strainer) and change the water until clear. Set aside to drain.

Cut the potatoes into rounds about a quarter inch thick, halving large ones into half rounds.

Add the grated garlic to the soft onions and cook a few seconds until fragrant.

Add the scallions and toss a minute or two until warm and soft; season with a little salt.

Add the potatoes and season with plenty of salt and black pepper.

Lay the cod fillets on top of the potatoes and season with salt, pepper and about a heaping teaspoon of thyme.

Pour in two and a half cups of stock, cover and cook over medium heat 30 minutes until the potatoes are fork tender.

Whisk two flat teaspoons of cornstarch into the lemon juice; taste the broth for salt and pepper first.

Pour the mixture in and swirl the pot rather than stirring, so nothing breaks up; cook 5 more minutes on low heat.

Add about two tablespoons of freshly chopped dill.