Check out this site (Lessons in Farming) about re-growing lettuce. Yes, it works, I have done it.
My garlic,and celery is also regrown from year to year. No GMO for me.
You can also do this with onions, pineapple, ginger, potatoes, carrots and more.
My garlic is wanting outdoors, but it is still too cold. In fact, it was snowing this morning. But I am so ready to get my raised beds started. I still don't have them prepped, as I am still recovering from my surgery (now at 6 weeks) and fighting a low hemoglobin. But, the last 2 days I feel like it has gone up some, I have more energy, and am napping less. For the last 2 weeks, I have been eating a lot of green leafy vegetables, and have doubled up on my iron. I think it is finally paying off. The doctor told me I would not see it go all the way back up for probably 6 months, so I still have 4 months to go of taking the higher iron and B12 doses. But, as soon as it gets to what he feels is a good number, he will release me back to normal activities.
So, hopefully one day this week I can get my beds topped with rabbit manure and add another layer of black soil. I already have my dirt (bought last fall at 70% off), the bags have been sitting by the beds all winter long, just waiting to be added this spring.