James Martin's cottage pie

Heat the oil in a large pan. Add the mince and cook until browned. Add the vegetable hot pot and carrots. Simmer for 10 mins. Meanwhile bring a large pan of water to the boil and add the two types of potatoes. Simmer for 15 mins or until tender. Drain, return to the pan and mash with the mustard, milk and butter. When the mince is hot, check the seasoning and spoon into an ovenproof dish. Spread the mashed potato over the meat and sprinkle with the cheese. Place under a preheated grill for 5-10 mins or until the top is beginning to turn brown.