Me: Hi, I'd like two hamburgers please.
FFWWADTOHH: Would you like cheeseburgers instead, they cost the same.
Me: No, thank you.
FFWWADTOHH: Would you like that in a meal with a small drink and fries.
Me: Sure, why not.
FFWWADTOHH: I can only get you hamburgers in meals if it's a Happy Meal.
Me: Uhm, do I look like someone who needs plastic toys? No Happy Meal, please.
FFWWADTOHH: So would you like to have a cheeseburger meal instead?
Me: No, no cheeseburger, please.
FFWWADTOHH: But we don't have hamburger meals.
Me: You know what? I'd like a cheeseburger meal, no cheese in the cheeseburger and a hamburger.
FFWWADTOHH: I never had a customer who didn't want cheese in their cheeseburger.
So rule number 2 when it comes to kashrut: we don't mix dairy with meat. And if you want to combine it with rule number 1: We don't eat cheeseburgers with bacon. Well, that's just a general rule, and I can't speak for other Jews who might or might not keep kosher.
So what else? G-d apparently has an issue with rabbit stew and seafood pizza, because hares and rabbits, juts like seafood (anything but scaled fish) are also not kosher. Really, any carnivorous animal isn't. But a safe bet: Coca Cola and Heinz ketchup in plastic bottles are kosher. So is Nutella sold in North America (and in Israel, of course). So fries made from scratch with Heinz ketchup and a coke with a jar of Nutella for dessert is a safe bet to feed your Jewish guest.