I sometimes make cedar planked salmon on our outdoor gas grill. I use
1/4" thick planks that we buy at the grocery store. The trick is
regulating temperature. Too low and the salmon cooks, but the plank
adds nothing to the process. Too high and the plank burns, giving a
charred taste. At the right temp, the plank emits wisps of smoke, and
that adds a nice flavor to the food.

OK, you ask, what's the magic temperature? I have not done this in a
few months, so I can't remember a numnber. Probably around 325F. But
it will probably depend on the thickness of the plank, how long it was
soaked in water, and the characteristics of the grill. You need to
experiment.

Not sure I would want to do this with an indoor oven, unless the room
had very good ventilation.

--
Julian Vrieslander