Combine the peppercorns, lime juice, fish sauce, sugar, oil, ginger, and chilli in a large bowl. Add the lamb to the marinade in the bowl and turn to coat. Set aside for 15 mins to develop the flavors.
Heat a barbecue grill or chargrill on medium high. Drain the lamb. Cook for 2-3 mins on each side, or until cooked to your liking. Transfer to a plate and cover with foil. Set aside and allow to sit for 5 mins.
Arrange the cucumber, tomato, onion, coriander, and mint on a serving platter. Sprinkle with cashew. Arrange the lamb on the platter. Serve with Custom Culinary™ Master’s Touch™ Jaew Sauce.