Put the flour and butter in a heatproof bowl and microwave for 1 minute at 600 W.
Take it out of the microwave and mix. Add the milk (don't mix it), then microwave again for 1 minute at 600 W.
Take it out of the microwave and mix it, then microwave again for 30 seconds.
Mix it again to finish!
Story Behind this Recipe
This is a versatile white sauce my parents used to make when I was young. It's surprisingly easy to make, so I recommend you give it a try.
It doesn't have much taste, so season it with salt or consommé to suit the dish you are making. In Step 2, the key is to heat it without mixing. If it hardens, quickly mix in a little milk while the sauce is still hot.