How do I make a curry sauce as smooth as a restaurant one?

The texture people are trying to reproduce at home has a specific origin. British Indian restaurants make a large pot of neutral base gravy in the morning, blend it to a smooth liquid, and then build each individual curry from it in a few minutes to order. A home curry made from chopped onions in twenty-five minutes cannot have that texture, because the texture comes from an hour of cooking and a blender.

What you'll need

• Onions — a large quantity
• Garlic and ginger
• Oil
• Blender or stick blender
• Carrot, red pepper, cabbage (optional)
• Ground spices

Step by step

1. Start with far more onion than a recipe suggests.Onion is the body of the sauce, not a flavouring. For a base gravy, six or eight large onions to one carrot and half a red pepper. Roughly chopped — it is all going in a blender.
2. Cook them long and slow with garlic and ginger.In plenty of oil with a lid on for the first twenty minutes to sweat, then uncovered for another twenty to thirty until completely collapsed and lightly golden. Not browned dark — a base gravy is meant to be neutral and slightly sweet.
3. Add water and simmer for another twenty minutes, then blend to a completely smooth liquid.Enough water to make a thin soup. Blend it in a jug blender for a good minute — longer than feels necessary. This is the step that produces the texture, and a stick blender does not get it as smooth.
4. Store the base and build individual curries from it.It keeps five days in the fridge and freezes in portions. To make a curry: fry garlic and ginger paste and your spices in oil, add tomato purée and cook it out, add a ladle of base gravy, then the meat or vegetables, then more base as it reduces.
5. Cook the spices out properly in the oil each time.A minute in hot oil with the paste, until the oil separates and the mixture darkens. The base gravy is deliberately bland; all the identity of an individual curry comes from this stage.
6. Finish with fat.Cream, coconut milk, butter, ground almonds or cashew paste at the end. Restaurant curries are noticeably richer than home ones and this is a large part of why they taste and feel different.
7. If you have no base gravy, blend the sauce you have.The single fastest improvement to any home curry: take the sauce out before the meat goes in, blitz it smooth, and return it. It transforms the texture of a twenty-minute curry with no extra ingredients.

Tips

• Blend for longer than you think. Restaurant base gravy is completely homogeneous, with no visible flecks, and thirty seconds in a jug blender is not enough.
• Cashew paste — a handful of cashews soaked in hot water and blended with a little water — gives the silky richness of a korma or a pasanda without dairy.
• Ground almonds stirred in at the end thicken and enrich in one move, and are traditional in several restaurant styles.
• Restaurants use more oil than a home cook is comfortable with. You do not have to match it, but a curry that tastes thin often needs fat rather than more spice.
• Freeze base gravy in portions of about 300ml. A curry takes ten minutes from frozen base and that is what makes the whole system worth it.

Questions people ask