To prepare the meat sauce, heat the olive oil in a large saucepan and cook the onions, carrot and celery for 5 minutes on a medium heat. Stir occasionally with a wooden spoon
Add in the minced beef and continue to cook for a further 5 minutes stirring continuously until coloured all over. Season with salt and pepper and cook for a further 5 minutes
Pour in the wine, stir well and continue to cook for 5 minutes until the alcohol in the wine has evaporated
Pour in the sieved tomatoes with the tomato puree and fresh basil, lower the heat and continue to cook for 1 hour, lid off, until you get a beautiful rich sauce. Stir occasionally. (After about 30 minutes, taste for seasoning).Preheat the oven to 180º
Meanwhile, to make the béchamel sauce, melt the butter in a large saucepan on a medium heat. Stir in the flour and cook for 1 minute until becomes a light brown colour. Gradually whisk in the cold milk, reduce the heat and cook for 10 minutes whisking constantly
Once thickened, stir in half of the parmesan cheese and the nutmeg. Season with salt and pepper and set aside to slightly cool
Spread a quarter of the béchamel sauce on the bottom of a deep ovenproof dish measuring approx. 30x25cm
Lay 4 lasagne sheets on top and if necessary cut them to fit the dish. It's important not to overlap the sheets or it goes claggy.
Spread over half of the meat sauce then top with a third of the remaining béchamel sauce
Lay 4 more sheets of lasagne on top and cover with the remaining meat sauce. Spread over half of the remaining béchamel sauce
Add a final layer of lasagne sheets and gently spread the rest of the béchamel on top making sure that you completely cover the lasagne sheets
Sprinkle with the remaining parmesan and scatter over the cubed butter. Grind some black pepper over the top
Cook on the bottom of the preheated oven for 30 minutes then place the dish in the middle of the oven, raise the temperature to 200º and continue to cook for a further 15 minutes until golden and crispy all over
Remove the dish from the oven and leave to rest for 10 minutes