Heat the oil in a heavy pan then add the chopped onion and stir for a few minutes with the heat on high. Add the ginger, garlic and green chilli (if using). Stir for 30 seconds then put the heat down to very low. Cook for 15 minutes stirring from time to time making sure nothing browns or burns. Add the turmeric, cumin and coriander and cook, still very gently, for a further 5 minutes. Don't burn the spices or the sauce will taste horrid - sprinkle on a few drops of water if you're worried. Take off the heat and cool a little. Put 4 fl oz cold water in a blender, add the contents of the pan and whizz until very smooth. Add the passata and stir. Put the puréed mixture back into the pan and cook for 20 - 30 minutes (the longer the better) over very low heat stirring occasionally. You can add a little hot water if it starts to catch on the pan but the idea is to gently "fry" the sauce which will darken in colour to an orangy brown. The final texture should be something like good tomato ketchup. Warning - it WILL gloop occasionally and splatter over your cooker, it's the price you have to pay! It will also leave a smell all over the house - so keep it ventilated!!!!
Once you have the basic curry sauce, you can make the Chicken Madras (my favourite!) Mum's favourite is the Chicken Massala - she is going to send me her recipe. She uses the same basic curry sauce!
This is the basis for many of the restaurant-style curries! It makes between 8 and 9 fl oz of sauce - enought for 2 main course curries, or a main course and some side dishes. If you need to make more, it doubles really well, but obviously takes longer to cook. You can also freeze it in small amounts if you want to make a quick 1 portion curry! ______________________________________________________________________ Per Tbsp: 133 Calories; 14 g Fat; 2 g Sat Fat; 0 mg Cholesterol; 6 mg Sodium; 3 g Carb; 0.57 g Fiber; 0.58 g Protein.