Creamy Leek Gravy

Leeks cooked slowly enough go almost silky and thicken a sauce on their own. This is a gentle, sweet gravy rather than a big savoury one, and it is what you want over a chicken and leek pie, roast pork, or a plate of buttered potatoes. Keep the heat low the whole way through and do not let the leeks brown.

Ingredients

Makes about 400ml, enough for four plates

• 2 large leeks about 400g trimmed, sliced into thin half moons and washed well
• 35g (1 1/4oz) butter
• 1 bay leaf
• 1 tbsp plain flour
• 300ml (10fl oz) hot vegetable or chicken stock
• 120ml (4fl oz) double cream
• freshly grated nutmeg about a quarter of a nutmeg
• salt and white pepper to taste

Kit

• Saucepan with a lid
• Colander
• Wooden spoon

Method

1. Slice the leeks thinly and wash them properly in a colander under cold water, working the layers apart with your fingers. Grit hidden in a leek will ruin the whole pan and there is no way to get it out later. Shake them as dry as you can.

2. Melt the butter in the saucepan over a low heat, add the leeks and the bay leaf and stir to coat. Put the lid on and let them sweat for fifteen minutes, stirring every few minutes. They should go pale, floppy and sweet with no browning at all.

3. Take the lid off, stir in the flour and cook for a minute. The leeks will have released some liquid, so it may look wetter than a normal roux, which is fine.

4. Add the hot stock a third at a time, stirring after each addition. Bring it to a gentle simmer and cook uncovered for five minutes, until it thickens and the leeks start to break down into the sauce.

5. Fish out the bay leaf. Taste and season with salt and white pepper now, before the cream goes in, because dairy blunts salt and you will end up over doing it if you wait.

6. Turn the heat down to the lowest setting and pour in the double cream. Warm it through for two to three minutes at a bare simmer without letting it bubble properly.

7. Grate in the nutmeg off the heat, taste one last time and serve. For a smoother sauce, blitz half of it with a stick blender and stir it back in.

Tips worth knowing

• Low and slow is the whole technique. Browned leeks taste bitter in a cream sauce, so if you see any colour appearing, drop the heat and add a splash of water.
• Use the green parts as well as the white, just slice them thinner and give them a couple of minutes head start. Throwing away the greens wastes about half the leek.
• Nutmeg goes in at the end and off the heat. Its aroma is volatile and simmering it for ten minutes leaves you with almost nothing.
• White pepper suits this better than black, both for looks and because it has a slightly earthy heat that sits well with leek and cream.

Keeping and reheating

Keeps three days in the fridge, covered, and thickens a lot as it cools. Reheat slowly with a splash of stock, stirring. It freezes for two months, though the leeks soften further, so it is better blitzed smooth before freezing.

Questions people ask