I always say leek and potato but I imagine there will be regional roots as to which way round it goes. My scottish friend says fork and knife instead of knife and fork.
I would think it depends on what proportion of vegetable is in it, as in more leeks than potatoes if said that way round. I call it potato and leek because I put more spuds in it.
Possibly because in enouncing the word 'potato' it's broken up into 'paw-tay-to', whereas 'leek and' is more flowing as 'lee-kand'. Ease of pronunciation is one of the things that historical linguists love to delve into to plot the changes in languages over time. Just a thought.
In a legal sense, leek and potato has to have more leek than potato, 'though whether it goes on weight or volume I don't know! We call it l and p, just made a big batch, as well as the first pea and ham of the season.
Reading the replies so far led me to believe that we probably mostly say leek and potato all bar a few exceptions. But each related question underneath this post is about potato and leek! There must be regional variations.
Yep healthfield or vegetable stock can be used. Sweat leeks in butter add chopped potatoes add stock simmer till pots are soft, liquidise or mash contents, thicken if needed with a little cornflour reheat add seasoning to taste and serve. Mine is the no cream added version.
I always thought that the main incredient should be listed first and that was the law.
When buying fruit juices this does not seen to apply as some of the first named of mixed fruits sometimes are only 5% of the total volume, as in Raspberry and Orange.
For commercial products the greatest ingredient must be listed first, so it is Potato and leak. If you make it yourself you can call it what you like.
There are a few exceptions, for example most commercial sausage rolls are around 30% sausage 70% pastry but they still call them sausage rolls.