Gently bring milk to the boil in a medium saucepan. In a separate saucepan, gently melt the butter. Add flour and cook over low heat for a few minutes.
Once milk is boiling, transfer a little at a time to the butter mixture, continuously whisking to prevent lumps. Bring mixture to the boil and stir continuously. Simmer for 10 minutes and adjust seasoning if desired. Pass béchamel through a sieve to remove any lumps.
TO START
Preheat oven to 180°C.
MAKE THE SAUCE
Gently heat some oil in a large fry pan. Once hot, add onion and garlic and cook for 2-3 minutes. Add mushrooms and cook until soft. Then add the veal and brown, stirring to ensure there are no lumps. Add the parsley, and season with salt and pepper to taste, then add wine and allow it to evaporate. Add the Ricotta sauce, bring to a simmer and cook for 2 minutes. Set aside to cool.
ASSEMBLE THE LASAGNE
In a rectangular baking dish, spread a thin layer of béchamel on the bottom of the dish then cover with a layer of Lasagne sheets. Put a layer of béchamel, then a layer of the veal and mushroom sauce. Sprinkle with Provolone and Grana Padano cheese and cover again with Lasagne sheets. Repeat this process four times.
BAKE
Bake Lasagne in pre-heated oven for 20-25 minutes and allow to rest for 5 minutes before serving.
