Preheat oven to 180C fan.
Peel the potatoes, cut them into small chunks, and cover them with cold water in a saucepan.
Cut cauliflower florets into similar size pieces and add them to the saucepan of potatoes.
Bring the saucepan of potatoes and cauliflower to the boil, and then simmer until the contents are soft (15 – 20mins). Set aside.
Meanwhile in another saucepan, over a medium heat gently brown the mince, breaking it down with a wooden spatula. Once the mince has browned remove it from the pan with slotted spoon and put it aside, leaving the beef fat in the saucepan.
Sweat the onions and carrots in the beef fat for about 8 minutes until soft. Add back the browned mince and crumble in the stock cube, stir to mix the ingredients well.
Once the stock cube has been fully dissolved, add the tin of tomatoes and cook gently for a couple of minutes. Season to taste.
Spoon the mixture into an ovenproof dish and allow cooling.
Meanwhile, drain the potatoes and cauliflower and mash together well with a potato masher and season to taste.
Spoon the mash over the mince mixture until you have a roughly flat surface.
Mix together the grated cheese and breadcrumbs and spread this mixture evenly over the top of the mash.
Bake in the oven for 30 – 35 minutes until the topping is brown and crisp. Then allow to cool a little before serving.
Garnish parsley (optional)