World's Easiest Garlicky Green Beans Stir Fry

fresh green beans (preferably long thin “French” beans, but any type will work)

peanut oil

chopped garlic

large yellow onion, cut in half top-to-bottom and then into slivers the same size as the beans (next time I’d probably just use the whole onion)

salt

water (plus a bit more if you check and the pan seems dry)

oyster sauce (comes in a bottle near the Asian foods in any major supermarket)