Ian,
I can sympethyse :-\with you i am having the same trouble, I have been on the road for a while travelling and have now just moved into a house with proper cooking facilities so i have been busy making base sauce over the weekend.? I finally cooked a prawn madras last night and it was ok but not there.? The best effort to date was last year when in the UK i used the Baasar Mix that Raygraham sent to me in the base sauce.
I am pretty sure my problem is overspicing which is resulting in a powdery taste in the final dish.? Also i am having trouble with the oil that i spoon off the base sauce as it gets onion particles in and if left at room temp starts to spoil very quickly.
I am only using a hand blender stick thing as well which leaves quite a thick base but i suppose you can add water to thin it out when cooking.
This site has grown big now and there are loads of recipes to try so i will just carry on until i hit the jackpot, ive been close before but it all seems to have slipped away which really does re-enforce the fact that experience counts.....

Heres the base sauce recipes i use
ingredients
4 large onions
1 green pepper
1 carrot (4-6in)
1/2 tin of tomatoes blended
1 cup of veg oil(standard coffee cup)
1/2 bunch of fresh coriander
3/4 litre of water
chop all ingredients put in pot boil for 30 mins
remove from heat add(these spices are your curry powder to use with the final curries)
2dsp turmeric
1 dsp chilli powder
1dsp ground coriander
1dsp cummin
1dsp Hot Curry Powder
mix well return to heat for 30 mins on simmer with lid onstirring occassionally. and there you have it remove the oil from the top before blending then return it to the sauce oh just blend to the consistency of puree for no more than a minute. if you have precooked you chicken and rice in the time for the sauces cooking time you will have cooked base form scratch to final dish in 90mins max. you can use this with any of the final recipes on this forum and don't be put off because there is no garlic/ginger in the base all i ask is for someone to try you will not be disappointed.And this is the Prawn Madras Recipe (Cheers Pete i do enjoy reading your posts)
I managed to get another demo at a restaurant.
The chef even let me cook some of it!
Here you are:-
Prawn Madras
Thawed Frozen ?Ocean Beauty? Prawns (about twenty)
Curry gravy oil (kept in a ghee pot on stove)
1 tablespoon garlic ginger puree (very runny)
1 desertspoon chilli powder
1 desertspoon curry powder mix
2 desertspoons tomato puree (very thick paste)
Curry gravy (soup consistency)
Gas ring on maximum all the time
Heat 2 tablespoons of curry gravy oil for a minute
Add 1 tablespoons of garlic ginger puree
Cook for a couple of minutes
It doesn?t brown at all, just turns a bit darker and small bits solidify
Add the chilli powder, curry powder, tomato puree and half a ladle of curry gravy (in that order)
Stir then let bubble away for five minutes
Stir and add two more ladles of curry gravy
Five more minutes than get the prawns and squeeze the water out of them, before adding to the pan
Cook another three minutes then add a little curry gravy oil
All in all it takes about 15 minutes
No lemon juice, coconut or fresh coriander used!