large handful mixed, soft herbs (we used mint, coriander and Thai basil), to serve
2 limes, juiced
½ onion, finely chopped
2 tbsp fish sauce
1 tsp sweet chilli sauce
1 red chilli, finely chopped
1 tbsp toasted rice powder (optional)
Finely chop the coriander stalks and combine with the oyster and soy sauces. Lightly season, then tip into a sandwich bag with the steak. Massage the marinade into the meat, then put in the fridge for up to 3 hrs, but at least 1 hr.
Put the dipping sauce ingredients in a bowl, finely chop 3/4 of the coriander leaves and add them too. Taste the sauce – if you like it sweeter, add a little more sweet chilli sauce; if you prefer it more salty, add a little extra fish sauce. Set aside.
Heat a frying pan over a high heat and, once very hot, cook the steak for 2-3 mins each side, depending on how well done you like it. Rest the steak for 5-10 mins before slicing and serving on a bed of herbs, with the sauce on the side.