The spices listed above are just suggestions; I encourage you to play with combinations. The most classic, simple combination would be clove, cinnamon, and bay leaf. I personally love pink peppercorns, cinnamon, bay leaf, and juniper berry. You can also make them with no spices at all, and that’s just great too.
To begin, slice the ends off the lemons, just a tiny bit to remove the nubs, you shouldn’t see the flesh, just the pith, after you slice.
Stand the lemon on one end, and slice it down the middle, almost all the way through, but stopping when you have about half an inch left. Make another cut perpendicular to that one in the same way. The lemon should be quartered lengthwise, but still in once piece. See the photos above for reference.
Using a spoon, sprinkle course salt all over the inside of the lemon, covering all of the flesh surface area.
Place the lemon cut side down in to a sterilized jar, and press it to flatten and release it’s juices. Press it down as much as you can. Sprinkle another teaspoon or so of salt over the top along with a pinch of your desired spices.
Repeat with remaining lemons until no more will fit when you press them down. If they aren’t already covered in their own juices, top them off with some boiled water that has cooled to room temp or with additional lemon juice.
Seal and let them sit in a sunny spot for a month, shaking periodically to evenly distribute the salt.
After a month, enjoy. I store them in the fridge at this point. To use, discard the flesh, lightly rinse the peel, and dice it or slice it however you like.
