Cut 6 Meyer lemons as follows: quarter them (almost) going from just below one end almost down to the other. The lemon will remain intact, but if you squeeze it by pressing the two ends towards each other, some juice will ooze out and the segments will be accessible. Using ¼ cup kosher salt total, press a generous teaspoon of salt into the open segments of each lemon. Squeeze the lemons into a wide-mouth quart canning jar, along with the rest of the salt. Be sure any juice that comes out the lemons as you squeeze them makes its way into the jar. Add juice of 2-3 more lemons (Meyer or otherwise). Add water if necessary, or more lemon juice, to fill jar.
Seal jar with lid. Invert several times to mix contents and help salt dissolve. For the next 7 days, leave jar on counter, inverting each morning. Place in refrigerator after 7th day.
You can make these with any kind of lemon, but Meyer lemons work well, and they are only available in the wintertime.