Chef Thomas
Anchovy Sauce
A proper white sauce sharpened with pounded anchovy, the old Georgian trick for waking up a piece of poached fish or a slice of roast lamb on a Sunday in spring.
Culinary Explorer
A cooking platform built around craft, culture, and the stories behind what we eat.
Onion Sauce
Created by Chef Thomas
A gentle, old-fashioned onion sauce, the kind that goes alongside a roast leg of lamb on a Sunday and makes the whole plate feel looked after.
Sauces & Condiments
British
Comfort Food
10 min
Active Time
35 min cook•45 min total
Yield6 servings
This is a Sunday sauce. Specifically, the sauce that sits in a small jug next to a roast leg of lamb, waiting its turn while everyone helps themselves to potatoes and arguing about whether the meat is done. Onion gravy gets all the attention these days, but onion sauce is the quieter, older thing, and on the right plate it's better.
It's a béchamel, essentially, made with milk that has been gently bothered by a bay leaf and a few peppercorns, then thickened with a butter and flour roux and stirred through with onions that have been coaxed into softness over a low heat. Nothing about it is clever. Nothing about it needs to be. The onions go sweet without going brown, the milk goes silky, and the whole thing tastes of a kitchen that has been paying attention.
I grew up eating this with mutton, which nobody seems to cook anymore, and lamb, which everyone does. It works with both. It works with a piece of poached chicken on a tired Tuesday. It works with a baked potato if that's the kind of evening you're having. A recipe is a conversation, not a contract.
I wrote it down in the notebook years ago and the note next to it says: "Sunday lamb. Rain. Three for dinner. Made the sauce. They asked for more." That's the whole brief, really.
The technique, the tradition, and the story behind every dish.
Discover Culinary ExplorerIngredients
onions
Quantity
3 large
peeled and finely chopped
unsalted butter
Quantity
50g, plus a knob extra
plain flour
Quantity
30g
whole milk
Quantity
500ml
bay leaf
Quantity
1
black peppercorns
Quantity
a few
nutmeg
Quantity
a small grating
freshly grated
fine sea salt
Quantity
to taste
white pepper
Quantity
to taste
double cream (optional)
Quantity
1 tablespoon
| Ingredient | Quantity |
|---|---|
| onionspeeled and finely chopped | 3 large |
| unsalted butter | 50g, plus a knob extra |
| plain flour | 30g |
| whole milk | 500ml |
| bay leaf | 1 |
| black peppercorns | a few |
| nutmegfreshly grated | a small grating |
| fine sea salt | to taste |
| white pepper | to taste |
| double cream (optional) | 1 tablespoon |
Equipment Needed
- •Heavy-bottomed saucepan
- •Small saucepan for infusing the milk
- •Whisk
- •Fine sieve
Instructions
- 1
Infuse the milk
Pour the milk into a small saucepan with the bay leaf and the peppercorns. Bring it just to the edge of a simmer, then take it off the heat and leave it to sit while you start the onions. Ten minutes is enough. The milk will pick up a quiet, herby sweetness that you won't notice individually but will miss if it isn't there.
Don't let the milk boil. A skin will form on top, which is fine, you can lift it off later. But scorched milk is something else, and there's no rescuing it. - 2
Sweat the onions
Melt the 50g of butter in a heavy pan over a gentle heat. Tip in the chopped onions with a generous pinch of salt. Stir them through the butter, put a lid on, and let them sweat slowly for fifteen to twenty minutes, stirring now and then. You're not after colour. You want them soft, translucent, and smelling sweet rather than sharp. If they start to catch or take on any gold, the heat is too high. Lower it.
Chop the onions more finely than you think you need to. This sauce should be soft and spoonable, not chunky. Big pieces of onion fight against the cream of the sauce. - 3
Make the roux
Push the onions to one side of the pan, or scoop them into a bowl if it's easier. Add the extra knob of butter and let it melt. Scatter in the flour and stir it into the butter to make a pale paste. Cook this for a minute or two, stirring constantly. It should smell faintly biscuity, not raw. This is the bit that thickens everything that comes after.
- 4
Bring it together
Strain the infused milk through a sieve, discarding the bay and peppercorns. Pour it into the pan in three or four additions, whisking well between each so no lumps form. The first splash will go thick and pasty. Don't panic. Keep adding and whisking and it will loosen into a smooth, glossy sauce. Stir the onions back in if you took them out. Let it bubble gently for five minutes so the flour cooks out properly.
If you do get lumps, a quick blitz with a stick blender will fix it. No one needs to know. - 5
Season and finish
Grate in the nutmeg, just a little, you should sense it rather than taste it. Season with salt and white pepper. Taste it. Then taste it again. If the sauce feels at all austere, stir in the spoonful of cream right at the end. It softens everything and gives it a quiet richness. Keep it warm over the lowest possible heat until you're ready to serve, stirring occasionally so a skin doesn't form on top.
Chef Tips
- •Whole milk, not skimmed, not semi-skimmed. The fat carries the flavour and gives the sauce its proper texture. A béchamel made with thin milk tastes like a béchamel made with thin milk, which is to say, nothing much at all.
- •White pepper rather than black. It's a small thing, but a pale sauce flecked with dark pepper looks distracted. White pepper disappears into the sauce and leaves only the warmth behind.
- •If you're serving this with lamb, spoon a little of the meat juices from the roasting tin into the sauce just before serving. It pulls the plate together and gives the sauce a savoury depth it can't quite reach on its own.
- •Don't be afraid of the salt. A bland onion sauce is a sad thing, and milk-based sauces need more seasoning than you'd think. Taste, adjust, taste again. Trust your tongue.
Advance Preparation
- •The sauce can be made an hour or two ahead and kept warm over the lowest heat, or in a bowl set over a pan of barely simmering water. Stir occasionally to stop a skin forming.
- •It will keep in the fridge for up to two days. Reheat very gently in a small pan, whisking in a splash more milk to loosen if needed. Don't let it boil or the texture will turn grainy.
Frequently Asked Questions
Nutrition Information
1 serving (about 178g)
Calories
185 calories
Total Fat
12 g
Saturated Fat
8 g
Trans Fat
0 g
Unsaturated Fat
3 g
Cholesterol
34 mg
Sodium
230 mg
Total Carbohydrates
15 g
Dietary Fiber
1 g
Sugars
8 g
Protein
4 g
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