Spread Five Tastes Curry Paste over steak and leave in the fridge to marinade for 1 hour.
Heat oil in a non stick frypan or wok, cook steak to medium doneness, approximately 3-4 minutes on each side. Remove from heat and rest while preparing salad.
Combine fish sauce, lime zest and juice, palm sugar, sesame oil and chilli together. Mix well.
Gently toss cucumber, tomatoes and herbs. Arrange on a serving platter. Cut meat into thin slices and place on salad, drizzle with dressing and sprinkle with nuts.