Preserved lemons are a popular Morrocan and Middle Eastern ingredient, typically found in tagines and stuff. You can buy them, but you might as well make them, its so easy, it just takes about a month.
Here, I used Meyer Lemons which are not as sour as regular lemons. Cut an X through the top of the lemon, going most of the way down, just leave it connected at the bottom. Fill each lemon with salt (I used kosher salt, French gris sea salt and Hawaiin Alaea salt) and smash all the lemons into the jar, so some of the juice is released. Toss in some chili flakes, bay leaf, coriander and fennel seeds and top it off with some more lemon juice if necessary to cover all the lemons. Leave it on the counter for a couple days then stick it in the fridge for a few weeks. You can then use the rinds in a variety of dishes. Check out the risotto recipe below.