Instructions

1. Stir together the marinade ingredients in a mixing bowl
2. Break the tuna into biggish chunks and drop into the bowl
3. Coat the fish well with the sauce then put in the fridge for 2½ hour or so
4. Heat wok (or large frying pan) well and add the extra groundnut oil
5. Remove the tuna from the marinade and add to the pan
6. Stir fry for a couple of minutes, add the sesame oil and serve