Step 1.Combine the marinade ingredients in a large bowl. Add the steaks and set aside to marinate for 10 minutes.
Step 2.For the dressing, whisk together fish sauce, lime juice and sugar.
Step 3.Heat oil in a frying pan over high heat. Cook steaks for 3-4 minutes each side (medium-rare) or until cooked to your liking. Remove the steaks from the heat and rest for 10 minutes before cutting into thin slices.
Step 4.Place the onion, cucumber, tomato, chillies, mint, spring onion and sliced steak in a large bowl. Add about half the dressing and mix. Taste and add more dressing if needed. Toss to combine. Serve with steamed rice (optional).
