1Heat oil in a pan and fry the mince until browned. Add the vegetables(carrots & onions & garlics), then cook on a gentle heat until soft.
2Add flour and tomato purée, increase the heat and cook for a few mins before adding the stock, and thyme. Bring to a simmer.
3By this time the gravy should be thick. If a lot of liquid remains, increase the heat slightly or add few flour to reduce the gravy a little.
4Meanwhile, make the mash. In a pan, cover the potatoes in water, bring to the boil and simmer until tender, then drain well.
5Mash well with the milk and butter.
6Spoon meat into a ovenproof dish. Pipe or spoon on the mash to cover. Sprinkle cheddar on the top.
7Put in oven for 1 hr 30 mins until the topping is golden.
To get really smooth, creamy mash, use a potato ricer or sieve. To stop the mash sinking into the filling, allow the meat to cool before topping with the mashed potato.