Place the lettuce in a big salad container and add about 1/2 cup of salt. Let sit for about 20 minutes but not more than 30. You want to try a little bit of lettuce and make sure is salty but not too salty. After the 30 minutes you'll rinse it once, that's why you want the lettuce itself to be salty.
While you wait on the lettuce to absorb the salt go ahead and wash and chop the other ingredients. Remove the skin of the carrots and reddish and slice it diagonal. Mash the garlic and cut the green onions about 1/4-1/2".
Once you have rinsed the lettuce you will add the rest of the ingredients in the same bowl. Mix it very well.
You can eat it right away, but it is better if you let sit for about an hour. Serve it over sticky rice like Calrose.