Cook the pasta in a large pot of rapidly boiling salted water according to the packet instructions. Add the frozen vegetables when the pasta has 2 minutes left to cook.
Drain the pasta and vegetables, reserving some of the pasta water.
Mix reduced cream, onion soup, vinegar. Combine the Kiwi dip sauce with the pasta and vegetables and add a little extra pasta water if necessary for a silky texture. Place the pasta in a heatproof dish. Top with grated cheese, potato chips and chives. Place under a hot grill for 3-5 minutes until the cheese melts and golden. Serve immediately.