Heat half the oil in a large, nonstick frying pan and stir-fry the beef in batches for 1–2 minutes. Remove with a slotted spoon and keep warm.
Heat the remaining oil in the frying pan and stir-fry the onion for 4–5 minutes until softened, then add the garlic, chilli, star anise, cardamom, cinnamon, green beans and carrot. Stir-fry for 6–8 minutes.
Return the beef to the pan with the fish sauce and the ground bean sauce. Stir-fry for 3–4 minutes or until heated through. Remove from the heat and sprinkle over the chopped herbs just before serving.