Start by melting the butter in a saucepan and then after adding the flour stir continuously until a paste forms. Then slowly bit by bit add the milk and whisk it by hand until it thickens up. Finally, add some grated cheese, & grated nutmeg to taste (you can add English mustard too). Simple, easy and quick. Add it to pasta for a cheap easy meal. You could add leftover chicken, ham, and bacon to jazz it up a bit.