In a small pan, mix all the marinade ingredients – all the ingredients except the tempeh. Mix well.
Add the tempeh and turn it over in the marinade several times to coat it.
Put the pan on the stove on a low heat, keeping it covered. The marinade will start to bubble and reduce.
Remove the lid to turn the tempeh over every 10 minutes or so, until the liquid is mostly dry and the tempeh smells amazing.
Transfer to a paper towel-lined plate to drain any remaining oil, then serve hot with whatever else is for dinner. We enjoyed it with some rice and veggies.