Hi I'd say that "to do the dish" means that you pick out a recipe and then make it However - and you are quite right - to do the dishes is to wash up the dishes after a meal It's a strange case where the plural makes a real difference - Sam did the dish, Peter did the dishes [= Sam made the meal, Peter washed up afterwards] Dave
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.