First bring the milk with the bay leaf to the boil and remove from the stove.
Melt the butter in another saucepan. Add the flour and sweat for about 2 minutes. You don`t want the mixture to turn brown. Remove the bay leaf from the milk and slowly pour the milk into the mixture while stirring. Stir until smooth. If lumps have formed, go through once with the hand blender. Bring slowly to a boil and simmer until the sauce thickens. Season to taste with nutmeg, salt and pepper.
Now layer the sauce and pasta plates alternately. It starts with béchamel sauce. Then put in pasta plates, tomato sauce, pasta plates, béchamel sauce, etc. The top layer should be sauce. Sprinkle the cheese on top.
Bake in a hot oven at 180 ° C for about 35 minutes.