Quarter the lemons from the top to within 1/2 inch of the bottom. Gently spread them without breaking the bottom and pack them with salt and then reshape the fruit.
Place 1 tablespoon salt on the bottom of a sterilized one pint mason jar.
Pack in the lemons and push them down, adding more salt and the optional other spices, between layers. Press the lemons down to release their juices and to make room for the remaining lemons. Cover the lemons with the spring water and leave enough space for the oil.
Pour the vegetable oil and seal the jar. The vegetable oil has no effect on the actual flavoring except that it works as a seal and protects the lemons from air contact during the preservation time.
Let the lemons ripen in a cool dry and dark area for at least 30 days before reopening.
To use, rinse the lemons, as needed, under running water, remove the pulp if desired.
Preserved lemons, sold loose in the markets (Souks) of Morocco, are one of the indispensable ingredients of Moroccan cooking, used in fragrant lamb and vegetables Tagines, recipes for chicken with lemons and olives, and salads. Their unique pickled taste and special silken texture cannot be duplicated with fresh lemon or lime juice.
Sometimes you will see a sort of lacy, white substance clinging to preserved lemons in their jar; it is perfectly harmless, but should be rinsed off for aesthetic reasons just before the lemons are used. Preserved lemons are rinsed, in any case, to rid them of their salty taste.
Cook with both pulps and rinds, if desired
There is no need to refrigerate after opening. Preserved lemons will keep up to a year, and the pickling juice can be used two or three times over the course of a year.
Tagines are Moroccan slow-cooked meat, fruit & vegetable dishes which are almost invariably made with lamb. Although not authentic, beef can be used as a substitute and turns out great as well.