You can approximate wok hei with a cooking blow torch, as theorized/discovered by Kenji Lopez-Alt (summary write-up / experimentation by one of his colleague he

You can approximate wok hei with a cooking blow torch, as theorized/discovered by Kenji Lopez-Alt (summary write-up / experimentation by one of his colleague here : https://www.seriouseats.com/hei-now-youre-a-wok-star-a-fiery-hack-for-stir-frying-at-home https://www.seriouseats.com/hei-now-youre-a-wok-star-a-fiery... )