In a large frying pan dry fry the mince. Once the mince is evenly browned, drain off the excess fat then add the tinned tomatoes, tomato puree, and stock and bring to the boil. Simmer over a medium heat until the sauce has reduced and thickened then set aside.
Pre-heat the oven to Gas 4, 180°C, fan 160°C.
In a small saucepan, melt the butter over a medium heat then blend in the flour. Off the heat, add a third of the milk a little at a time, stirring with each addition until it is a smooth paste. Stir in the remaining milk then return to the heat and bring to the boil, stirring continuously. Boil for 1-2 minutes until the sauce thickens. Remove the pan from the heat and stir in the grated cheese until it has all melted in.
Spoon an even layer of the meat sauce into the bottom of a large, ovenproof dish. Cover this with lasagne sheets and top them with a third of the cheese sauce. Repeat until you have used all the ingredients. Finish on a layer of cheese sauce. Place the dish into the oven and bake for 25-35 mins until the top is golden and bubbling.
Please note: this recipe has been created and uploaded by a member of the Tesco Real Food online community. Tesco does not test customer recipes so cannot accept responsibility for the content, validate the results or answer queries regarding them.