One staple of North African and Arabic cooking is pickled lemons. There is a recipe for chicken tagine with green olives and pickled lemons that gets made in our home on a regular basis. I have found pickled lemons at the Arabic grocery store, but they are not nearly as good as what you can prepare at home. With a few hours of preparation time, you can make enough pickled lemons to last a year.
To make pickled lemons, start by cutting the ends off of each lemon. Standing the lemon on one end, make a cut down the the center, stopping short of cutting the lemon into two halves. Turn the lemon over and make another cut at a 90 degree angle to the first, again stopping short of cutting the lemon in half. You should now have a intact lemon that is cut into quarters. Squeeze the lemon slightly to open and fill one cut with coarse salt. Holding the lemon as to not lose the salt, turn it over and fill the cut on the opposite end.
Fill a clean jar with the lemons. I have a French jar with an air-tight lid, but you can also use plastic wrap. The lemons will need to be tapped down before sealing the lid. I have read to keep the jar in a cool place while the lemons pickle, but Shadi says in Yemen they place the jar out in the hot sun.
As the lemons pickle, the jar will fill with juice. I tap down the lemons periodically until they are completely submerged. When this happens, add a bit of oil to the top to prevent mold. It will take at least three weeks before the lemons are ready. I store my pickled lemons in the refrigerator, and I am still using the ones I prepared a year ago.