I'm originally from the PNW and I've godda tell you, I've never seen and indian cooking fish that way... :laugh:
Joking aside, I've cooked many fillets on planks of all sorts and cedar is my least favorite. It's still good, but I really don't care for the strong cedar flavor that comes out of a new plank.
If I use cedar I fill up a 5 gal bucket with water, insert all the planks place something heavy on top to keep them submerged and come back a week later and do it again.
The water will be dark dark brown/black from all the tannins and stuff that is pulled out of the planks, even the 2nd time, heck I tried it with a plank 1 time to see how many buckets it would take to get clear (ish) water after soaking... it was somewhere around 7 or 8.
After soaking, I let the plank sit out and dry. Resoak for 1/2 hr before you use and now you'll get a much milder, slightly cedar flavor that I think compliments the fish, not over powers it.
BTW - maple or alder are my favorite planks to use.