Lightly squash the tomatoes with the fish sauce, lime juice and zest, and the chilli sauce. Cook the noodles following pack instructions. Meanwhile, heat the oil in a wok and stir-fry the onion, carrot and pepper for 5 mins or until softening. Add the cabbage and cook for a few mins more. Remove the vegetables from the pan, add the lamb and cook for 5-8 mins so that it is still tender and juicy. Take the pan off the heat, toss in the noodles, vegetables, tomato dressing and mint, and serve.