Hi
I think there can be a large discrepancy in the measures. I made it before I saw curryhells post (cheers for that) and the measures I got (peeled and chopped weights)
Onions:650g
Carrot: 100g
Potatoes: 350g
Coriander: 20g
That is about a 50% difference in the weight of the onions which is sure to make a difference to the taste and texture to the dish.
Also a handful of coriander is massively ambiguous and for new (and not so new

) curry makers, as correct a measure as possible can only be a help IMHO.
One of the reasons Cory's recipes are so popular and work so well.
I have made the basic and enhanced gravy so will report back when I make a curry. First impressions: too much heat for milder dishes.
regards
Barry