Lasagna rolls with ham and mushrooms

Lasagne rolled with ham and mushrooms
Remove the stems from the mushrooms, wipe them and slice them finely. Cook them in a sauté pan with a knob of butter, salt and pepper, until they no longer release water, set aside.
Prepare the béchamel by melting the butter in a saucepan, add the flour, whisk for 20 seconds then add the 40 cl of milk little by little. Whisk until it thickens between each addition of milk. Take 100 g that you reserve, salt and pepper the rest and add the Parmesan then the mushrooms and 1 tbsp of parsley sprigs, mix.
Cut the lasagna in 2, cover with a tablespoon of mushroom béchamel, spread well then place the slice of ham and another 1 spoon of béchamel, roll up and place in the dish.

Repeat the operation for the 10 slices, lengthen the remaining béchamel with the 10 cl of milk and cover the lasagna with it
Lasagna rolls with ham and mushrooms
Sprinkle with the remaining Parmesan and bake for 25 to 30 minutes at 180°C (to be monitored according to ovens).
During cooking, baste with the more liquid béchamel from the bottom of the dish