Combine lamb with marinade ingredients in bowl; cover, refrigerate 1 hour, or overnight.

Place noodles in bowl, cover with boiling water, stand 5 minutes, drain.

Heat half the oil in wok, add half the lamb mixture, stir-fry until browned all over, remove from wok. Repeat with remaining oil and lamb.

Heat extra oil in wok, add onions and broccoli and stir fry until lightly cooked.

Stir in blended cornflour and water, soya sauce and peanut butter, stir until mixture boils and thickens.

Add lamb and noodles, stir until heated through.