Place about a tablespoon of the salt in a mortar or small bowl. Add minced herbs and grated lime zest and grind together with pestle or wooden spoon. The mixture will get damp or pasty as the herbs break down and release moisture. Blend this mixture into the remaining salt, grinding further or not, depending on desired coarseness of the salt. Spread salt on a flat pan and dry in the oven at low temperature of about 200–225° for about an hour. When dry, store in a tightly closed container.