Clean, wash and mince with the mixer, onion, carrot and celery.
Separately, dice the pancetta or bacon and then finely chop it on the chopping board.
Transfer the bacon into a saucepan, and let it ‘sweat’ gently over very low heat for a few minutes, so that the fat melts.
Add the oil and the chopped vegetables, which you will wither for 7-8 minutes, turning occasionally so that they do not darken too much; halfway through, add a pinch of salt.
Turn up the heat, add the minced meat and brown it for 4-5 minutes; pour in the wine and let it deglaze, stirring gently. Add salt, add the tomato pulp, bring back to the boil and lower the heat to a minimum.
Put the lid in half and continue cooking for at least 2 hours, adding a little boiling water when necessary, because at the end the sauce must be dense but always soft and creamy; towards the end of cooking adjust salt and pepper.
Pour a small amount of sauce and a couple of tablespoons of béchamel sauce into a baking tray, spreading them well on the bottom. Form a first layer of lasagne, pour a few tablespoons of meat sauce and béchamel sauce on top and sprinkle with plenty of Parmesan cheese.
Using this procedure, make further layers until all the ingredients have been used up. Finish with a layer of béchamel sauce and Parmesan cheese and bake the lasagne at 200°C for about 30 minutes. Remove from the oven, leave to rest for about ten minutes and then serve.
