Hello, Pigale!
I had a look in Chambers Dictionary and the meaning (I think) they give is, "knack of using", which seems fine.
Does not give the origin though. I will have a look at Brewer's and see what they say.
It sounds American to me, too. As does "hung jury".
Now, I only have a bacon roll when I go out with the young ones to a cafe! It is very easy to order.
I mortified my 17 year old granddaughter a month ago when we went to a cafe and I asked the serving lady what a panini was. My granddaughter was aghast.
Street cred in tatters!
So, I am safe enough with a bacon roll!