2 tablespoons of plain flour
2 tables spoons of olive oil
Half an onion or perhaps a couple of shallots
1 bay leaf
Mix the 2 tablespoons of flour with the 2 tablespoons of olive oil to form a paste this is called a roux.
Fish out the onion/ shallots , cloves and bay leaf.
Then gradually add the milk to it thickens to a consistency you like.
You can add further ingredients to your sauce , I added cheese.
My friend swears by a pinch of mustard powder too.
Move over Nigella .... Maybe ?!