Placeholder draft — replace with the real essay.
Every recipe that asks you to reduce a sauce “until it coats the back of a spoon” is really just asking for starch and salt in the right ratio. Pasta water already has both, for free, in the pot you were already boiling.
The case for keeping the puddle
A mug of the cloudy stuff, held back before draining, turns a dry pan of garlic and oil into an emulsified sauce in under a minute. No roux, no cream, no extra dishes.
I keep a coffee mug next to the colander now, specifically for this. It has become one of those small kitchen habits that quietly makes everything slightly better without asking for credit.