I got to Tadka then realised this is what we know as Tarka Dal, good read Phil. 
Yep - good find, Phil.
I've always known the frying of spices, etc in hot oil to add to a dish at the end as 'tarka' as well, but I guess it's just down to regional variations.
Whatever you call it, it's never ceased to amaze me how a simple and otherwise bland bowl of lentils can be lifted to dizzy heights.