This is very useful recepie,with few extra ingredient you can make chicken,seafood or mutton curry with different flavors
For approximately eight main course dishes, and many different dishes

Ingredients:

2 lb (900g) cooking onions
2 oz (50g) green ginger
2 oz (50g) garlic
2¾ pint (I litre 570ml) water
1 teaspoon salt
1 tin (8oz/225g) tomatoes
8 tablespoon vegetable oil
1 teaspoon tomato puree
1 teaspoon turmeric
1 teaspoon paprika

Method:

Step One
Peel and rinse the onions, ginger, and garlic. Slice the onions and roughly chop the ginger and garlic.
Put the ginger and garlic into a blender with about ½ pint of the water and blend until smooth.
Take a large saucepan and put into it the onions, the blended garlic and ginger, and the remainder of the water.
Add the salt and bring to the boil. Turn down the heat to very low and simmer, with the lid on, for 40-45 minutes.
Leave to cool.

Step Two
Once cooled, pour half the boiled onion mixture into a blender and blend until perfectly smooth. Absolute smoothness is essential. To be certain, blend for at least two minutes. Pour the blended onion mixture into a clean pan or bowl and repeat with the other half of the boiled onion mixture.
Wash and dry the saucepan. Reserve about four tablespoons of the sauce at this stage to use in cooking the chicken and lamb.
Freezing. Freezing is best done at this stage.

Step Three
Open the can of tomatoes, put into the rinsed blender jug, and blend. Again, it is important that they are blended perfectly smooth, so blend for two minutes.
Into the clean saucepan, pour the oil, tomato puree, turmeric, and paprika.
Add the blended tomatoes and bring to the boil. Turn down the heat and cook, stirring occasionally, for ten minutes.
Now add the onion mixture to the saucepan and bring to the boil again. Turn down the heat enough to keep the sauce at a simmer.
You will notice at this stage that a froth rises to the surface of the sauce. This needs to be skimmed off.
Keep simmering for 20-25 minutes. Stirring now and again to prevent the sauce sticking to the bottom of the saucepan.
Use immediately or cool and refrigerate for up to four days.