Pommes Mousseline :Puréed Potatoes

You'd think it would be simple, huh?

• Boil 1kg potatoes in salted water
  
• Smoosh/mill/grind/tammy
• Add 100 g butter
• Add 250-300 ml hot milk
• Ta Dah!

But notes include these 8 (eight!) additional points

• Cook really thoroughly (5 mn more than you think)
• Drain & then dry in 180c oven for 5 mn
• When grinding they must be really hot (do in batches)
• Butter quickly - when still hot
• sticks the purée together & gives body
• Not too much milk - it's not potato soup
  
• To keep warm put over a water bath
• Cover with film right on the surface of the potatoes - or a plate if all else fails
• Puréed potatoes cannot be successfully reheated - don't even think of it.

Alternative implementation: no butter, no milk, just use olive oil - very tasty. Not to be done today but reportedly worth trying