Mix the dressing ingredients together and set aside.
Oil and season the fillet steak. Heat a heavy based frying pan over a high heat and sear the steak for three minutes on each side. Allow to rest for five minutes before thinly slicing with a sharp knife.
Cook the potatoes in a pan of salted water as per instructions. When the potatoes are just cooked (soft), toss the sugar snaps into the water for 30 seconds. Drain everything and wait for the potatoes to cool before slicing them into wedges.
Mix together the beef, potatoes, sugar snaps, carrot, cucumber, scallion, shallot, bean sprouts and herbs. Pour over the dressing and toss.