So, this is seriously easy and I wish I had tried it sooner. It's all over the place. You might have seen it before, but in case you haven't, put clean, dry, chopped lettuce in a mason jar. Screw on the lid. Put it in the fridge. That's it. Sounds too simple, but it really works.
Just keeping it real y'all!
I may have tested it out by chopping up this lettuce before vacation, and *cough* serving it after we got back. You do need to make sure your lettuce is actually dry, so it doesn't mold.