Combine the butter and cake flour in a large heat-resistant bowl and place one in the center of the oven without covering with the plastic wrap. (Do not insert the Baking tray)

Select MANUAL MICRO, choose MICROWAVE 600W and press ENTER.

Set knob to about 1 minute then press START.

After heating step 1 up, mix until smooth with a whisk.
 

Add milk to step 2 little by little until smooth. (Do not insert the Baking tray)

Select MANUAL MICRO, choose MICROWAVE 600W and press ENTER.

Set knob to about 1 minute then press START.

After cooking, mix, then extend the cooking time for 1 minute and press START .
After that, mix and extend the cooking time for another 3 minutes and press START . 
 

When done, mix lightly and add salt and pepper to adjust its taste.

<Important Point>
Once you can make some lines with the whisk, the texture is suitable.No film will be made if you directly stick the plastic wrap on the surface without air.