How to... make a fish soup

Daniel Pfyl, hospitality management lecturer at Otago Polytechnic, shares some professional techniques to make your cooking easier. This week, simple fish soup or stew.

1 leek
1 carrot
a knob of butter
1 tomato
fish stock (see earlier Trick of the trade [1])
a pinch of saffron (optional)
chunks of white fish
prawns (optional)
1 egg yolk
2 Tbsp cream
lemon juice
finely chopped parsley

PICTURE ONE: Julienne the leek and carrot (cut into thin matchstick pieces).

PICTURE TWO: Melt a little butter in a saucepan, add leek and carrot. Stir, then allow the vegetables to sweat, cooking slowly without browning. Add a pinch of saffron if using, then fish stock. When it comes to the boil, add fish and allow to poach gently.

PICTURE THREE: Peel a tomato (dip briefly in boiling water so the skin will slip off) and cut off the outer flesh, leaving the seeds behind. Chop flesh finely.

PICTURE FOUR: In a bowl, whisk the egg yolk and cream - this is a liaison for thickening the sauce.

PICTURE FIVE: To serve, put the chopped tomato in soup bowls. Place the fish and the julienned vegetables on top. Keep warm.

PICTURE SIX: Put the liquid back on the stove top briefly. Check seasoning and add a little lemon juice. Spoon a ladleful of liquid into the egg yolk and cream mixture and whisk.

PICTURE SEVEN: Quickly pour this into the stock in the saucepan and whisk again, but do not allow it to boil or it will curdle.

PICTURE EIGHT: When thickened, ladle the sauce over the fish and vegetables and sprinkle with finely chopped parsley.