When people who clearly have never cooked a meal for themselves prepare one on film. The whole process.
We recently watched a movie where a woman was preparing dinner but she’s chopping whatever the hell she was chopping like it was the first time in her life that she had ever held a knife. Sometimes they even use the completely wrong knife for whatever the task is that they’re trying to do. Other times, they’re constantly stirring something like boiling noodles or sauces that don’t need to be stirred. All kinds of dumb things that are obviously done just to give the actor something to do with the props around them but that make the character look incompetent instead.
Even worse is when whatever they’re doing doesn’t even make sense within the context presented in the film, e.g. dicing a lime for drinks instead of cutting slices or wedges, using a pepper grinder on fruit, making another character taste something that would be scalding hot, etc.
Close runner-up is when characters go to a bar and order “a beer” or some other generic version of something. Just make up a god damn brand name, fer chrissakes.