Hi TN
Did you get the onion sauce sorted? I had good results by starting it on the top of the stove then sealing the pan with tin foil and letting the sauce cook in a very low oven for about 3 hours, some of the onions dissolved and thickened the sauce, the end result was fabulous.
The vindaloo sauce is amazing, used it instead of tomato puree in a jalfrezi, fantastic.
CA, the book just lists several 'core' preparations and sauces and the 'recipes' are really just different combinations of such sauces etc., so it's difficult to explain them without reading the book, surely Down Under Amazon would get it for you, it's worth trying anyway, it's not perfect or the whole answer but what is?
Cheers
CoR