Whisk together lime juice, palm sugar, fish sauce, sesame oil, soy sauce, ginger and garlic in a jug. Place the tenderloin in a glass or ceramic dish. Drizzle with half the dressing. Cover with plastic wrap and place in the fridge, turning occasionally, for 2 hours to develop the flavours.
Preheat a barbecue grill or chargrill pan on high. Cook steak on grill for 2-3 minutes each side for medium or until cooked to your liking. Transfer to a plate. Cover with foil and set aside for 10 minutes to rest.
Place the tomato, cucumber, onion, chilli, mint, coriander, basil, peanuts and lime leaves in a large bowl. Thinly slice steak across the grain and add to the salad. Drizzle with remaining dressing and gently toss to combine. Divide salad among bowls and serve immediately.
1 1/2 tablespoon fresh lime juice
1 tablespoon finely chopped dark palm sugar
1 tablespoon fish sauce
2 teaspoon sesame oil
1 teaspoon soy sauce
2 teaspoon finely grated fresh ginger
1 garlic clove, crushed
150 gms beef tenderloin
1 tomato, halved
1 cucumber, halved lengthways, thinly sliced diagonally
1 red onion, halved, cut into thin wedges
2 long fresh red chillies, halved, deseeded, thinly sliced lengthways
1 bunch fresh mint, leaves picked, large leaves torn
1 bunch fresh coriander, leaves picked
1 bunch fresh Thai basil, leaves picked, large leaves torn
55gm toasted peanuts, coarsely chopped
4 kaffir lime leaves, centre veins removed, finely shredded