Infuse the hot milk with the three cloves of garlic, bay leaves, thyme and a little grated nutmeg. Leave for 10 minutes. Melt the butter in a pan on a low heat, then add the flour and cook out for five minutes, stirring regularly.
Pour the infused milk mixture (strain it first to get rid of the garlic etc), little by little, into the flour and butter mix (roux), stirring all the time, with the heat on low, so it will not burn on the bottom of the pan.
Then add the pepper and bring to a slow simmer for five minutes at a slow temperature, stirring constantly, before you add the cheese.
Cook the pasta according to the packet instructions.
Wash the spinach in a colander and then pour a kettle full of boiling water over it. Once it has wilted, refresh with cold water. Squeeze as much water out of it as you can.
Chop the spinach and mix through the cheese sauce.