Well, this depends on your interpretation of "low-stress".
I can only recommend what I have experience with. Right now I do two part-time jobs that really work for me in terms of responsibilities, hours and environment.
1. Substitute teaching. Honestly, it's babysitting, although it can be intellectually stimulating depending on what kind of things the kids are learning about. Most days I can just sit back and relax and surf the internet... like right now for instance
2. Pizza delivery. Most of this job is spent driving around listening to music. Social expectations are low. Free pizza sometimes.
Obviously, these jobs will not be right for everyone, but they certainly meet my definition of "low-stress." And they make ends meet... sort of.
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Plantae/Magnoliophyta/Magnoliopsida/Fabales/Fabaceae/Mimosoideae/Acacia