My Collins dictionary says that a posset is a drink of milk curdled with ale or beer, etc, flavoured with spices, and used as a remedy for colds.
then you probably felt much cosseted by your posset.
Nowadays, though, this lovely word has come to mean something rather different:
A modern posset only really has two ingredients - cream and sugar - but they're usually flavoured with something, and that is usually an acidic fruit (most often lemons) and/or something boozy.
Take 600ml of double cream, 200g of caster sugar and the zest of three lemons, plus 75ml of the juice. Heat the sugar and cream in a saucepan, stirring, until the sugar has melted. Bring to a simmer and bubble gently for a minute. Take off the heat and stir in the lemon zest and juice. Divide between pots, cover, cool, and then refrigerate for at least three hours.
I don't know if it cures colds, but it has to be worth a try.
Word To Use Today: posset. This word has been around since the 1400s, when it was spelled poshoote but no one really knows from where it came before that.