Heat oil in a hot wok until the surface seems to shimmer slightly. Deep fry beans for 1 – 2 minutes or until just tender and slightly wilted. Using a slotted spoon, remove from oil drain on kitchen paper and set aside.
Carefully drain hot oil from wok and wipe clean with kitchen paper.
In the clean wok, combine hoisin sauce, garlic, salt, extra oil and chilli. Toss in reserved beans and turn up heat to high. Stir-fry beans 2 -3 minutes, coating them in the sauce. Serve immediately, with a little extra salt, if desired