Soak the Cedar planks in water. Ideally you want to do this for a few hours before you start cooking, but i have soaked them for 15 minutes before while i prepped and it turned out fine. The soaking will reduce the odds of the cedar plank catching fire on you in the grill.

Chop your greed onions and leave them aside for later. Melt a half stick of butter and set it aside for later. If it's starts to get solid just crank the heat up again to quickly melt it.

Put the Salmon Filet's on the Cedar plank and season them with Salt, Pepper and the Onion powder. I always eyeball this based on who i know is eating the fish and how much seasoning they typically like.

Crank your grill up to 375 degrees or so. Place the plank in the grill. Make sure to open the grill frequently to check on the fish. The soak should prevent the outright burning of the plank, but if you see an edge catch fire, put out with the spatula and move the plank to a different sport of your grill.