A classic Dry Martini without bitters and garnished with cocktail onions in place of an olive or a twist. On those two distinctions, all are agreed. However...
I’ve been of the impression that you go with an odd number of onions or olives etc out of superstition. I love tradition so things like odd versus even with the garnish appeals to me. Can someone comment on the use of two in a Gibson?
I think the received wisdom is that two onions references the décolletage of a Gibson girl. I ALWAYS add two onions because I'm not superstitious, and because three is clearly too many onions, while one is woefully insufficient.