Preserved lemons are popular in Moroccan and Indian cooking, but I like to use them as an ingredient for almost every dish. They can liven up any meal. A jar of preserved lemons can be expensive and full of preservatives, but they're very easy to make at home. You can add peppercorns and spices to your jar, but I like them very basic.
Mash the lemons into your dish or slice up and use as a condiment. Only use clean utensils when taking the lemons out of the jar. This will keep in your fridge for at least a few months (mine have lasted up to 6 months).