Today I did it.
There was this 'things you should know about coffee' thing and part of it was 'never add cold milk but get a jar and shake up some milk and it's like a flat white' or some such. All because of...
KEEWATIN
(Yes, you know who you are)
So here is what it was:
STEP ONE
I did look for a jar. I failed. But this plastic food storage thing looked ok so I put milk in it. The coffee was just finishing up in the espresso can on the stove.