Having only a couple of days ago posted a thread calling for people to consider freeing themselves from the desire to emulate resturant food, it might seem a little odd that I'm now posting a thread on making a resturant curry sauce.
It is just that after posting the thread, I once again started musing on how to get what the average British Indian Resturant (BIR) gets. Instead of attacking the problem on the basis of ideas and sauces other people had already posted, or, indeed, old attempts of my own, I tried to think about what must go on in BIR's, many of whom have very small kitchens, and yet manage to produce a large range of dishes, often to an excellent standard.
One thing is for sure: they can't prepare each dish from scratch, marinating the meat first as one would with Indian home cooking. Considering what's possible, and what I've seen from a couple of open plan takaway kitchens, each of which seemed to have an unbelievably small area available for the number of dishes they could come up with, I came to the following conclusion (which, I'm sure many others have come to before - hence this sub forum).
They obviously have one or two basic sauces from which all other sauces are derived (probably one with youghurt, and one without). These sauces will be minimally spiced. The only spces that will be added are those that need to cook for a long time with the other ingredients in order to completely combine, and gain that elusive depth that BIR sauces seem to have.
Clearly, a restuarant preparing as many dishes as the average BIR will want a basic sauce with no keynote spices, as these would interfere with the spicing of the individual dishes.
From my experience, it seemed to me that these minimum spices are probably limited to aesofetida, turmeric and cumin. Corriander may also be one of these base spices.
The other important point about BIR cooking is that it is obviously impossible for them to keep cooking up small batches of basic sauce. They'd get into a terrible state trying to keep up with varying demnds. Neither, I'm pretty sure, will they throw away the left over sauce at the end of each sitting.
My guess is that they keep a large pot of basic sauce on the go all the time, and top it up as the level goes down with batches that they either cook on a continuing basis, prepare and chill/freeze or even buy in.
So the sauce they are actually using could well contain very small quantities that are weeks old, with ever larger proportions of newer batches. Whether or not the presence of elements of the sauce that may have been being cooked for days actually has any effect on the flavour/texture I don't know.
One further point. The sauce must be sufficiently liquid that it can be left without glooping or sticking. If there was any tendency to stick, then at some point it would stick, and the whole system would eventually grind to a halt.
So, this is what I did.
Heated about 200ml of oil (yes, I know most basic sauces use more, but bear with me - I couldn't see any logical reason to, and this worked).
Added a level tablespoon of chopped ginger, and a similar quantity of chopped garlic. The temperature of the oil was such that the garlic and ginger made a quiet sizzeling sound, and gradually turned brown over the course of about ten minutes. This is to allow it to cook thoroughly without burning.
About two minutes before the garlic and ginger was browned, I added: 1/2 tsp aesofetida, 3 tsp Turmeric, 3 tsp ground cumin, and 1/2 tsp ground chilli.
Two minutes later I added four large sliced onions and stirred them around to let the oil cover them (don't know why - superstition, perhaps). I then added enough water to almost cover the onions.
This mixture was then allowed to simmer quite gently for an hour.
At the end of the hour a can of chopped tomatos was added - simmering continued.
An hour later this mixture was pureed with a hand blender.
Up to this point I had been cooking it in a large stock pot so that I could use the blender without covering te kitchen with sauce. I now transfered the mixture to two saucepans. I added a teaspoon of ground corriander to one, and set them both on a bare simmer, and left them for 4 hours, just giving them the occasional stir to make sure they weren't sticking (they weren't).
At the end of this time, what did I have ?
Well, two pots of something that looked exactly like the sauce that a typical Madras or vindaloo comes in. The taste, whilst obviously not being anything like a good curry (although I'd swear I've been dished up with a "Madras" that was made with something like this), has that unmistakeable depth that BIR curries have.
The sauce with the corriander has a slightly brighter, fruitier flavour. I don't think it was necessary to add it to the basic sauce, but it wouldn't do any harm if your final curry should have corriander flavour. It seems to be a very robust spice that does not degrade with long cooking.
The next step was to try the sauce to actually make a dish.
To do this I simply fryied some onion until golden, added some diced chicken and cooked until the chicken was done. Five minutes before the end I added a half tsp of garam masala.
The result was something that as far as I could tell cound not be distinguished from a BIR Madras. I've yet to try the experiment, but I'm pretty sure that if I put it in a foil container, and offered it to someone alongside a good takeaway, they would never be able to say which dish came from the resturant. (They might be able to differentiate it from one that came from a particular resturant with which they were familair, of course).
Well, sorry for the ramble, but this is something I've been trying to do, off and on, for a long time, and I wanted to share some of the thoughs behind what I did, as well as the recipe. I'll post a short version as well.