Say I walk into a Jewish bagel shop staffed by Jews who keep kosher. I suppose such a shop might offer bagels with cheese, and also bagels with beef, though presumably they would ordinarily be prepared separately, since consuming meat and milk products together is forbidden by Jewish law. ;j
My question is, would they make me a beef and cheese bagel if I asked for it? More generally, do kosher laws apply to the preparation of food for gentiles, or only to the preparation of food for Jews?
One kosher deli I used to go to had gotten into trouble under a previous ownership, so they may have been being extra careful, but they would not serve a corned beef and swiss sandwich inside. They would sell you a corned beef sandwich to go and wrap a slice of swiss cheese separately and hand it to you.
And would you be allowed to eat this sandwich inside, or would you be expected to leave the premises to consume it?
There’s a rule (derived from the Torah’s saying three times that you shouldn’t cook a kid in its mother’s milk) against deriving any benefit from a mixture of meat and milk. In most situations where a Jew might want to make food for gentiles, the Jew would presumably be deriving some benefit from doing so (otherwise, why do it?). So Jews can’t fix non-kosher food for gentiles if the non-kosher food involves a mixture of meat and milk.
However, it is permitted (in Deuteronomy 14:21) to give or sell meat from an animal that died on its own (was not properly slaughtered) to a gentile, even though Jews are forbidden to eat the meat of that animal. So a Jew would be allowed to serve non-kosher-slaughtered meat to a gentile.
Jews are not supposed to touch the carcasses of unclean animals (Leviticus 11), so presumably serving something like pork or shellfish to a gentile is out, too.
The kosher laws also include rules about dishes- you are not supposed to use the same dishes for meat and dairy foods. And Leviticus 11:33 says that, if an unclean animal falls into an earthenware (ceramic) dish, you are supposed to break the dish- there’s no way to make it kosher again. So I would imagine the kosher deli would be quite sensitive about what they allowed customers to eat on their dishes.
Actually, they probably wouldn’t serve both meat and dairy foods. All of the kosher restaurants I’ve been to have been one or the other, not both. A deli that also sold groceries (a lot of kosher delis do) would be likely to sell both meat and dairy products, but they would probably only prepare one or the other (most likely meat dishes) in their kitchens.