How to Make It
Set the salmon skin side down on a large rimmed baking sheet and rub with the aquavit. Let stand for 10 minutes. In a small bowl, combine the brown sugar, salt, coriander and cardamom. Rub the sugar mixture all over the salmon. Cover and refrigerate for 36 hours.
Light a grill or heat a grill pan. Pat the salmon dry and cut it into 6 portions. Rub the salmon skin and the grill with oil. Grill the fish, skin side down, over moderately high heat until the skin is crisp, about 1 minute. Cover the grill and cook the fish over moderate heat until rare within, about 6 minutes. Serve hot or chilled with horseradish mayonnaise and a radish salad on the side.