Mix sugar, salt, water, and anise flavored liqueur. Pour over salmon halves in a 3-inch deep pan. Marinate, chilled, in the brine mixture for 4 to 8 hours. Remove from brine and pat dry. Brush the salmon with oil. Season with wild fennel pollen, salt, and pepper. Place on Alder plank and soak in cold water overnight. Sometimes a nail through the tail end is used to hold the salmon in place. Lean the plank against an Alder wood fire that has mostly died down to very hot coals. Be careful not to let the plank catch fire. The heat and the smoke from the fire will cook and season the salmon. Serve right off the plank.