For the cheese sauceWarm the milk in a saucepan (don't allow to boil). In another pan, melt the butter and add the flour. Stir rapidly for about 2 minutes, remove from heat and add the milk, stirring constantly until thick and smooth.
Then season with a pinch of nutmeg, salt and pepper before cooking at low heat for 2 minutes. Remove from the heat and mix with two-thirds of the Parmesan cheese. Set aside.
For the lasagne'Preheat the oven to 180°C. Cook the chicken in water and your own choice of seasonings until tender for 10 minutes and leave to cool in the water before draining. Place the cutting knife in the food processor and cut the chicken into thick pieces. Set aside.
Then, using the food processor jug and the cutting knife, individually chop the onion, garlic, tomatoes, parsley and olives. In a saucepan, sauté the butter and the garlic, then add the chicken, tomatoes, olives and parsley and cook over low heat. Set aside.
In a glass ovenproof dish, assemble the lasagne by alternating the layers of cheese sauce, chicken and mozzarella, finishing with the cheese sauce.
Sprinkle the cheese on top and bake for 25 minutes.