You must peel green papaya before using it. I just use a vegetable peeler and then cut off the stem. If you have a medium or large green papaya (more than 2 pounds), cut the stem off first, stand the green papaya on its cut end and go at it with the vegetable peeler. Halve the papaya lengthwise and use a spoon to scoop out and discard the seeds. Note how it looks somewhat space alien-like inside. The white seeds eventually turn black during the ripening process.