Topic: Curry Base Sauce

[stewpot007]

Curry base #2

After much experimentation I think I?ve finally got a grasp of the grail of restaurant style taste. The secret, I?m convinced, comes down to the preparation of the base. In particular it comes down to the way the onions - the main component of the base ? are treated. Put simply, they need to be fried in order to draw out their natural sugars ? this is the ?authentic? sweetness you get in a takeaway or at a restaurant. The blend of spices is less fundamental. They may give each restaurant its subtle differences, but it?s the caramelised onions that give the authentic similarity we all seem to crave. It?s a long, protracted and messy process but worth it!
  Because it?s such a hassle you might as well make a largish batch (like a restaurant). This make 1 litre (approx)

Ingredients:

2kg chopped onions
10 good cloves of garlic
1 ?thumb? of ginger
1 medium potato boiled and then pureed in half a cup of water
2 bay leaves
6green cardamom pods split
1 dessertspoon of ground coriander
1 dessertspoon of ground cumin
1 dessertspoon of paprika
1 dessertspoon dried garlic powder
1teaspoon hot chilli powder
1teaspoon turmeric
1teaspoon of salt
1 litre of rapeseed oil

Method:

Stage 1
 Place onions, garlic cloves and ginger in a large pan with as little water as you can get away with to stop it sticking. About half a pint to a pint should do it. Put a lid on, bring to boil and then simmer over a low heat. The onions themselves should give up some moisture and collapse down a bit.
Stage2
 After an hour puree with a hand-blender (it should look similar to apple sauce). Now, with the lid off, (but definitely with a splatter guard on) cook down gently over a lowish heat for a further hour. Stir regularly to stop it sticking. What we?re actually trying to achieve is to remove all the water from the onion puree. This takes time. 
 Stage 3
After an hour add the litre of oil. It will spit horribly. Continue to cook down, with the lid off but a spatter guard on, stirring occasionally, until it has reduced significantly, almost stopped steaming and pretty much stopped splattering. Depending on your pan, initial water content of the onions, etc, this could take anything from 1-3 hours.
Stage 4
Now here?s the critical part. The alchemy. Raise the temperature to medium and allow slowly to become darker in colour (20-40mins). This is the natural sugar in the onions caramelising. As it gets darker it should taste increasingly sweet. It should begin to sizzle rather than gloop when stirred. It?s about right when it reaches a dirty, sandy colour.
 Add the spices, fry for a further three minutes.
Take off the heat and allow to cool for an hour. Then decant off the oil (don?t throw this away ? use it to cook the final dishes). What oil?s then left over can be added to make up a litre of oil for the next batch of base sauce. The taste should improve with every subsequent batch of base you make!
 Finally, add the potato and salt to the base. Refrigerate for at least 24hrs. This serves 2 purposes: firstly, the taste improves even more; secondly, there?ll be another deposit of oil that can be subsequently removed.

Tip. Once it?s removed from the heat and cooled a bit, it?s a good idea to pour it into a taller container. This makes decanting the oil off easier.