Cut the bread into 8-12 slices and spread them on a baking tray. Roast in a preheated oven (electric cooker: 225 °C/recirculating air: 200 °C/gas: level 4) for 6-8 minutes. Take out. Switch the temperature down (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3)
Heat the fat in a pot. Sweat flour in it. Stir in 200 ml water, milk and stock. Bring to the boil and simmer for about 5 minutes. Season to taste with salt, pepper and nutmeg. Cut the mozzarella into slices
Grease the casserole dish (approx. 28 cm long). Spread 1/4 of the Bolognese sauce on the bottom. Place half of the slices of bread on top and pour half of the béchamel on top. Spread half of the remaining bolognese sauce on top. Place the rest of the bread loosely on top. Spread the rest of the bolognese and béchamel in between. Place the mozzarella on top. Bake the lasagne in a preheated oven for about 30 minutes, garnish