I know it's a bit late, I've not tried this yet but will do at some point..
The first thing to make up is a batch of base curry sauce, this is another Indian restaurant secret, at the start of the day they will make up a huge vat of this sauce and every curry they offer is based on this sauce. The sauce isn’t specific to CTM, for example to do a Madras curry you would fry some ginger and garlic, add a tin of plum tomatoes (no juice), fry for a few minutes more, add about ¾ pint of the base sauce, add 2 tbsp of ground almonds, a few tsp chilli powder and viola.
Anyway I digress, for the base curry sauce you will need the following:
• 2 TBSP butter ghee (not vegetable although you can use that if you can’t get butter ghee)
• 1Kg Mild onions (Spanish red whatever)
• 75g Garlic
• 75g fresh ginger
• 1 tin tomatoes (liquidised)
• 2 TSP turmeric
• 2 TSP paprika
• 1 TSP coriander
• 1 TSP cumin
• 1 TSP tomato puree
• 2 UK pints (1.14 Litres) water
Yep that’s a lot of onions.
1. Chop the onions up roughly and place in a large saucepan,
2. liquidise the ginger and garlic in a little water and add that to the pan,
3. add the remainder of the water and bring to the boil, then leave to simmer for 45 minutes. The onions must be extremely soft.
4. This onion soup must now be thoroughly liquidised until its consistency is extremely smooth; it is this base that gives the Indian restaurant curry its texture and consistency.
5. Mix all 4 of the spices together in a bowl with a little water to make a paste.
6. Now put the ghee in a wok or karahi on a medium heat,
7. add the spice paste and fry for 20 seconds stirring all the time, no longer or they will burn.
8. Add the tomatoes, tomato puree and salt and cook for a further 5 minutes,
9. now add the onion, garlic and ginger mixture and bring back to the boil, simmer now for 20 minutes.
This is the base curry sauce and can now be frozen in batches for future use. About half a pint to a pint is good to make 4 portions depending on how much sauce you like.