Wash and scrub the lemons and dry thoroughly. Cut the pointy tip of the lemon and slice into quarters leaving about an inch intact at the bottom. Place a heaping teaspoon of salt into the bottom of a glass jar and top with the lemon cut side down.
Repeat with more lemons until the glass jar is full. Be sure to pack them tightly releasing their juices. Toss in the chiles if using. Seal the jar and let sit overnight.
If your lemons aren’t covered within 24 hours simply squeeze in some more lemon juice or add an extra lemon if you have room.
Keep shaking the jar each day for about a month and then they’re ready to be transferred to the refrigerator. At that point they’ll keep for about 6 weeks