Soak the birch wood plank in cold water overnight to prevent it from burning when you place it on the charcoal.
Light the grill. Grind the spices and herbs with a pestle and mortar. Mix in the rest of the ingredients for the salmon. Rub the flesh side of the salmon with the paste and let it sit for 15-20 minutes.
Spread the charcoal along the edges of the grill. Lay the seasoned salmon skin down on the soaked plank. To create indirect heat, place the firewood on the bottom of the grill with the charcoal surrounding the firewood. Place the plank with the salmon on the fire and put the lid on the grill. Leave the damper open for 5 minutes. Then close the damper and leave the salmon for about 10-15 minutes until it is nice and firm. Do not open the lid. Otherwise you will lose the wonderful smoke flavor.
Serve the salmon on the birch wood along with the pickled seaweed.