Preserved lemon or lemon pickle is a condiment that is common in South Asian and North African cuisine. It is also known as "country lemon" and leems.
Diced, quartered, halved, or whole, lemons are pickled in a brine of water, lemon juice, and salt; occasionally spices are included as well.
The pickle is allowed to ferment at room temperature for weeks or months before it is used, which is sufficient time to find a use for it.
When life gives you lemons, do something productive with them. Like literally anything else aside from preserving them.