I don't know if they still do it, but, back in the day, Taco Bell used to boast of the fact that they used real "Queso" cheese in their menu items. Now, anyone who took a minimal amount of Spanish in school (or has eaten in a Mexican restaurant) knows how stupid this claim is. "Queso" means cheese.
So now, whenever Megan is making a dish with cheese in it (which is often), I ask her if she is using real "Queso" cheese. I've asked it enough at this point that she knows it's coming. She bemoans the fact that it wasn't even really that funny the first time as I laugh and laugh.
I have other "anti-jokes" I use repeatedly. Like, if there is the slightest wisp of a cloud in the sky, I'll always say "I don't like the looks of those clouds", as if it could start raining at any moment. She's on to that one as well.