When to add leaves to the cooking process is a bit of a dilemma! I tend to grind up my dried methi leaf and add it with the spice mix and chillie early on, i.e. I 'flash-up' the oil 'till really hot add one small ladle of base (this has the same effect of making a paste with the spices and water, it reduces the risk of burning), and then add my spices, cookiing on a high heat for 30 seconds or so, then I add the remaining base etc etc.
I'm not sure if that's the right time to add methi, I've read conflicting advice on this, some add it as I do, some wet the whole dried leaves and add them near the end of the process. 'My' method seems to work but I couldn't say if its the best way!
Interestingly, curry leaves are typically added early on also: my Dad & brother went to a demo in the East End, and told me that the curry leaves were added to very hot oil, before anthing else. Yet fresh corriander is added just before serving (usually that is, except when it appears in some base recipies, then of course, by the time the finished dish is prepared the corriander has had quite a long time of cooking).
I'd be interested to hear other view on this.....