Irreversible binomials (part 2)

... another thing to note about toasties/toasted sandwiches is the order in which their fillings are listed. In the US, I'd have a toasted cheese or a toasted bacon and cheese, whereas in the UK, I'd be more likely to have a cheese and bacon. In both countries, it would be cheese and tomato (though, of course, the pronunciation of tomato would differ). These are what is known in the linguistics trade as "irreversible binomials": two words on either side of a conjunction (and in these cases) that idiomatically occur in a particular order. So, one says bread and butter rather than butter and bread and gin and tonic rather than tonic and gin. A generali{s/z}ation that one can usually make about such food binomials is that the first item is the one that's more "substantive"--the "meat", as it were, in the formula (hence meat and potatoes/meat and two veg, not potatoes and meat or two veg and meat). So, the gin is the stronger item in gin and tonic and it goes first, and bread is the heart of the bread-and-butter combination.

See full article at http://separatedbyacommonlanguage.blogspot.com/2008/04/toasty-and-toastie.html