Bolognese sauce: Finely chop the onion, sauté in the butter, grate in the garlic, add thyme, bay leaf, and oregano.
Let it simmer for 5 minutes while stirring.
Add the minced meat and crush it into fine pieces in the mixture.
Let it cook well for 5 minutes.
Finely chop the bell pepper and add it.
Peel the celery and carrots and chop them finely, add them along with the wine, passata, tomato paste, and balsamic cream.
Season with pepper and salt, bring to a boil and reduce the heat, let it simmer for 1 hour covered, stirring occasionally.
Béchamel sauce: Melt the butter in a saucepan, once it foams, add the flour all at once and cook for about 3 minutes.
Add half of the milk and stir vigorously to remove all lumps, add the rest of the milk and let it come to a boil. Mix in half of the cheese, season with pepper and salt, and grate some nutmeg if you are a fan, I certainly am. 😊
Take a large baking dish, spread 1/3 layer of the bolognese sauce in it.
Completely cover with lasagna sheets, place the 4 slices of ham open in it, cover with 1/3 of the béchamel sauce, fill with lasagna sheets, and repeat until everything is distributed, ending with a layer of bolognese and sprinkle the rest of the grated cheese on top.
Bake for 35 minutes in a preheated oven at 180°C.