Talking of dry roasting the spices, which I always do (but in a fry pan), I found this article interesting. 
http://www.azeliaskitchen.net/blog/dont-dry-roast-spices/
Martin
An excellent article, Martin.
It fascinates me to discover how things begin. (It's still a mystery to me, for instance, how, after tasting the foul bitterness of raw olives from the tree, someone thought "Brilliant. These will make fantastic oil when crushed".)
It hadn't occurred to me that dry roasting spices was born not necessarily for reasons of taste, but out of practicality to counter the damp of monsoon periods. (And I wasn't aware of the differences between Indian and European coriander seed, either.)
It's only 09:46, but already I've learnt something...