Here's a very useful primary source on the subject (and a gateway to a large number of other, similar sources, which would be useful for getting an idea of what a restaurant goer would experience in this time): http://menus.nypl.org/menus/29711 This is the menu of a hotel restaurant in NYC, used in May 1944. Something I like about this menu in particular is how they explain their limitations due to rationing to their customers in the red sidebar - for example, the restaurant is allotted points to secure items, and can't guarantee having several of their meat dishes.

In Sweden, dishes were calculated and rationing coupons had to be turned over. "Coupon-free" disheds were common, made from meat that was not part of the rationing system (crow and badger were common) or wild game (which was not part of the rationing either, but rare).