Leek and Onion Gravy

Leeks bring a grassy sweetness that onions do not have, and they give a gravy a green, spring like quality even in the middle of winter. This one stays deliberately pale and gentle, and it is what you want with roast chicken, a chicken and ham pie, or a plate of poached smoked haddock if you fancy something unusual.

Ingredients

Makes about 450ml, enough for four plates

• 2 large (about 400g / 14oz trimmed) leeks sliced into 5mm rounds, whites and greens kept separate
• 1 medium (about 150g / 5oz) brown onion finely chopped
• 40g (1½oz) butter
• 1½ tbsp (25g) plain flour
• 550ml (1 pint) hot chicken stock
• 3 tbsp double cream
• 1 tsp lemon juice
• salt and white pepper

Kit

• Saucepan
• Colander
• Whisk

Method

1. Wash the sliced leeks properly. Grit hides between the layers and there is nothing worse in a smooth gravy. Drop the rounds into a bowl of cold water, swish them about, then lift them out with your hands so the grit stays behind.

2. Melt the butter in a saucepan over a low heat, add the onion and the leek whites with a pinch of salt, and cook gently for 15 minutes without letting anything colour. Leeks scorch and turn bitter far more readily than onions do, so keep the heat low and stir often.

3. Add the leek greens and cook for another 5 minutes, until everything is soft and silky and has slumped right down in the pan.

4. Stir in the flour and cook for 2 minutes, keeping it pale. The mixture will be thick and cling to the spoon.

5. Add the hot stock in three goes, whisking well after each, then bring to a gentle simmer. Cook for 10 minutes, stirring occasionally, until it thickens to the consistency of pouring cream.

6. Take the pan off the boil, stir in the cream and the lemon juice, then season with salt and white pepper. Keep it below a full boil from here, because once the cream is in a hard boil can make it look grainy.

Tips worth knowing

• Keeping the whites and greens separate is worth the extra thirty seconds. The whites need fifteen minutes, the greens need five, and cooking them together means one is undercooked or the other is grey.
• The lemon juice is not there to taste of lemon. It is there to stop the cream and butter making the gravy feel heavy.
• If you want it smooth, blitz it with a stick blender before the cream goes in and it turns a lovely pale green.
• Do not throw away the darkest leek tops. Simmer them in the stock for ten minutes and strain them out, and you get more flavour for nothing.

Keeping and reheating

Fridge for 3 days only, because of the cream. Reheat gently without boiling. It can be frozen but the texture suffers a little, so if you plan to freeze it, leave the cream out and add it after reheating.

Questions people ask