What is Gravadlax or gravlax?

Gravadlax or gravlax — The traditional Scandinavian method of curing salmon, in which the freshest raw salmon is rubbed with a mixture of sugar, salt, pepper and fresh dill and left to cure until it has turned opaque. True gravadlax should be left to cure at a temperature of between 3°C and 4°C (about 37°F to 39°F) for three to four days. It's often served with a dill and mustard dressing or mustard mayonnaise.