Found it, based on my recent success with the natco base if I were to cook this again I would add an extra 3 TBSP of garlic paste.
Mark J Curry Gravy Base
10 onion base version
vegetable oil to cover large pan upto a height of 3/4 inch
3 tbl Garlic & Ginger paste
1 tbl curry powder
1 tbl Turmeric
1 lvl tsp Chilli powder
10 tennis ball sized onions, chopped
2 celery stick chopped
1 green pepper chopped
2 large carrots chopped
1 tsp Salt
1.5 lvl tsp Garamasala (Natco is very nice)
1 tin tomatoes (450g) - or pasatta
handful of fresh coriander ripped or chopped
2 tbl Knorr 'Touch of Taste' liquid chicken stock concentrate
water
1) Heat oil until hot add the garlic and ginger and fry until brown, keep stirring
2) Add curry powder, turmeric and chilli powder and stir fry. Add some cold water (few tablespoons) when it starts to stick to the bottom of the pan. This frees it up instantly
3) Add the onions, carrots, green peppers and celery
4) add salt and garamasala and mix around
5) add tomatoes then add boiling water to cover the vegetables by an inch
6) once up to the boil, add liquid chicken stock and simmer on lowish flame for 1 hour
7) Liquidise - easiest way is to use a hand blender straight into the pot
Boil hard for 10 mins - the top of the sauce rolls just like the base you may have seen in BIRs
9) cook on low for another 5 mins, leave overnight.
all measures are rounded spoons unless it says lvl