For the classic lasagna with Bolognese sauce, first prepare the bechamel: Melt butter, add flour and stir. Add hot milk, season with salt and nutmeg and bring to a boil. Set aside.
Grease a baking dish or square oven tray.From bottom to top: a layer of bechamel, a few drops of Barilla Sauce Bolognese, a layer with two rows of lasagna sheets.Repeat 5 times, alternating layers of sauce Bolognese, lasagna sheets, bechamel and grated Parmigiano Reggiano.(There must be enough bechamel left for the top layer).
Bake in the oven at 180 °C for 20-25 minutes.
Remove the classic lasagna with Bolognese sauce from the oven, let it cool for 10 minutes and serve.