Cook rice noodles in boiling salted water for 6 minutes. Drain and refresh in cold water. Drain again and dry off with a tea towel or paper towel before using. Place lamb in dish and cover with curry paste. Leave to infuse while cooking vegetables.
Spray capsicums lightly with oil then transfer to open grill. Turn to ensure even cooking. Remove after 2-3 minutes whilst still firm but seared. Brown lamb: first spray hot barbecue plate with oil, add lamb and cook each side for 3 minutes. Remove, cover with tinfoil and rest for 2 minutes.
Line a long platter with cos leaves. layer rice noodles over the base. Scatter over tomatoes, cucumber, grilled capsicums and red onions. Slice lamb into thick slices and pile on top.
Combine honey, lime juice, oil and whisk well. Pour dressing over salad and top with mint.