Heat the oil in a tick saucepan and stir in the flour.
Cook in an oven or on the side of the stove, stirring frequently until a medium brown colour is achieved.
Browned flour is produced by spreading flour evenly on a shallow tray and colouring in a moderate oven. The flour should be turned frequently during cooking to ensure an even colour. When ready it should be sieved and stored in an airtight container until required.
The roux must be allowed to cool before any liquid is added. This amount is sufficient for 500 ml of sauce.