Preserved lemons
Preserved lemons figure most prominently in North African cooking, in dishes such as tagines, and also appear across the Mediterranean and Middle East.
You can buy them in jars or prepare them yourself. Simply make several deep slashes into the lemon, pack the cuts with salt, then layer in a big jar, pressing down and adding lemon juice. The skin softens significantly and becomes much easier to eat.

Recipes with preserved lemons:
Couscous with preserved lemons