Heat the oil in a cooking pot. Brown the meat in batches, remove. Reduce the heat, wipe the cooking fat from the pan, add a little oil if necessary. Sauté the onions and garlic, add the tomato puree and cook briefly. Add the vegetables, continue to cook for approx. 2 mins., return the meat to the pan, mix. Pour in the wine and stock, bring to the boil, reduce the heat. Add the herbs, cover and cook for approx. 30 mins., stirring occasionally. Remove the herbs, season the sauce.
Heat the butter in a pan. Add the flour, cook over a medium heat while stirring with a whisk; the flour must not take on any colour. Pour in all of the milk at once, bring to the boil while stirring, reduce the heat, season, simmer for approx. 10 mins., stirring occasionally until the sauce is thick and creamy.
To assemble the lasagne
Spoon 4 tbsp of Béchamel sauce into the prepared dish. Place 3 sheets of lasagne on top, cover with ¼ of the meat filling. Repeat the process until the lasagne sheets and meat filling have been used up. Cover with the remainder of the Béchamel sauce. Sprinkle with parmesan.
Approx. 30 mins. in the centre of an oven preheated to 220°C. Remove the lasagne and leave to rest for approx. 5 mins.