I learned to make this white sauce from a top chef in London. It can be used as a base for loads of dishes. It is the easiest and the best recipe for a foolproof, lump-free sauce.
You can mix the oil and flour and leave in the fridge, using it as necessary for up to 6 months.
This is now my standard recipe for white sauce, I really like it! I mix the oil and flour in the saucepan and heat the milk in a cup in the microwave, then mix it in gradually, instead of heating the milk in the saucepan - just saves on washing up. - 09 Sep 2011
Took shortcuts. Added a small amount of warm milk to the oil and flour and then put the mixture into the saucepan rather than adding all the milk and then putting back in the pan. Was quicker and less messing about. - 01 Nov 2008
Exactly what I was looking for. I had to cater for 40 people with a cheap pasta dish. Bought 16 tins of Tuna (on offer 4 tins £3) added sweetcorn, garlic and herbs. Went down a storm ******* - 09 Jun 2011