Ingredients

Equipment Needed

• •Small heavy saucepan
• •Stick blender
• •Box grater
• •Fine sieve (optional, for extra gloss)

Instructions

1. 1

   Soften the onion

   Melt the butter in a small heavy saucepan over a low heat. Add the chopped onion and a pinch of salt and let it sweat slowly. You want it soft, sweet, and just barely starting to take on colour at the edges. This takes ten minutes or so. Don't rush it. The onion is doing most of the work in this sauce, and the slower it goes, the better the finished thing tastes.

   Chop the onion finer than feels necessary. The sauce gets blended at the end, but the smaller the pieces start, the smoother and quicker the cook.
2. 2

   Add apple, garlic and ginger

   Stir in the grated apple, the garlic and the ginger. The apple will collapse almost straight away into the buttery onions, going pale and soft. Cook for two or three minutes until everything smells fragrant and the apple has lost its raw edge. The kitchen should start to smell like the back room of a chip shop, in the best possible way.

3. 3

   Toast the curry powder

   Tip in the curry powder and the flour and stir hard for a minute. The mixture will turn thick and pasty and the spice will go from sharp and dusty to warm and toasted. Trust your nose. The moment it smells properly cooked, not raw, not burnt, you're ready for the stock. This step matters more than any other. Raw curry powder tastes of cupboard.

4. 4

   Add stock and simmer

   Pour in the stock a splash at a time, stirring after each addition so the flour loosens into a smooth sauce. Add the sugar, the soy and the vinegar. Bring to a gentle simmer and let it bubble away quietly for fifteen minutes, stirring every so often, until it's thickened to the consistency of single cream and coats the back of a spoon.

5. 5

   Blend and season

   Take the pan off the heat. Blend until completely smooth with a stick blender. The sauce should be glossy and the colour of an old penny. Taste it. It probably wants a touch more salt, maybe a tiny pinch more sugar if your apple was sharp. If it feels too thick, loosen with a splash of stock. Pour over chips, still hot, in a generous puddle. That's the whole job.

   If you want the proper chip-shop gloss, push the blended sauce through a fine sieve. It takes an extra minute and gives you that silky, almost lacquered finish.

Chef Tips

• •Use a cheap, mild madras curry powder, not anything fancy or single-origin. This is one of those rare cases where the supermarket tin is exactly the right ingredient. It's what gives the sauce its particular, slightly nostalgic flavour.
• •An eating apple works better than a Bramley here. Bramleys collapse to fluff and turn the sauce a bit grey. A Cox or a Braeburn holds its sweetness and gives you that gentle fruity backbone the sauce depends on.
• •Make a double batch and freeze half. It defrosts perfectly and means that the next time you fancy chips and curry sauce on a Tuesday, you're ten minutes away from dinner instead of forty.

Advance Preparation

• •The sauce keeps in the fridge for up to four days in a covered container. Reheat gently with a splash of water or stock to loosen.
• •Freezes well for up to three months. Defrost overnight in the fridge and warm through slowly, whisking to bring it back together.

Frequently Asked Questions

Nutrition Information

1 serving (about 220g)