Cod with Beurre Blanc & Leeks

📝 Ingredients

• 2 skinless cod fillets (about 150 g each)
• 500 g waxy potatoes
• 2 leeks (about 200 g each once trimmed)
• 15 g unsalted butter (for the leeks)
• 2 shallots (about 30 g each)
• 3 tbsp white wine vinegar + 3 tbsp water
• 2 tbsp light single cream, 12% fat
• 50 g very cold unsalted butter, cubed (for the beurre blanc)
• 1 vegetable stock cube + 750 ml water (for poaching)
• 1 bay leaf
• 5 g fresh chives
• Salt, white pepper

🍴 Utensils

• Saucepan with steamer basket
• Sauté pan with lid
• Small saucepan
• Large deep frying pan
• Whisk
• Slotted spoon

📖 Steps

1. Peel the potatoes, cut them into evenly sized pieces (about 4 cm) and steam them for 20 to 25 minutes with the lid on, until the tip of a knife slides in without resistance. Keep them warm, covered.
2. Meanwhile, trim off the roots and dark green parts of the leeks, split them in half lengthways and rinse under cold water, fanning out the leaves to wash out any grit. Slice into half-moons about 1 cm thick.
3. Melt 15 g butter in the sauté pan over a low heat, add the leeks and a pinch of salt, cover and leave to soften for 20 minutes, stirring now and then. They should become tender and translucent without browning: if they stick, add a splash of water.
4. Peel and very finely chop the shallots. Put them in the small saucepan with the vinegar and water, then reduce over a medium heat for 5 to 6 minutes, until only about 1 tbsp of liquid is left in the bottom. Remove from the heat.
5. In the large frying pan, bring 750 ml water to a simmer with the stock cube and bay leaf. Add the cod fillets, turn the heat right down (the water should barely tremble) and poach for 6 to 8 minutes, basting the tops, until the flesh is pearly and flakes apart.
6. While the fish is cooking, put the pan of shallots back over a very low heat and add the cream. Whisk in the cold butter one cube at a time, whisking constantly and waiting until each cube has almost melted before adding the next: the sauce should become frothy and coat the back of a spoon.
7. Make sure the beurre blanc never boils, or it will split and turn oily: if the pan gets too hot, take it off the heat for a few seconds while you keep whisking. Season with salt and white pepper and keep the pan off the heat, next to the still-warm hob.
8. Carefully lift out the fillets with a slotted spoon and drain them. Divide the melted leeks between the plates, place the cod on top, add the potatoes, spoon over the beurre blanc and sprinkle with snipped chives. Serve straight away.