A Nicoise Salad in Winter, and The Rules

Perhaps Will Shakespeare lived in Northern California and craved a salad in winter when he spoke of those days, green in judgment and cold in blood; or maybe I'm just projecting because, as recently as yesterday, I was talking about this salad I had made, borne of winter crops, which still I took to be a very-nearly-classic Salade Nicoise, but for the outrage of tomatoes in absentia, and it got me thinking: What, really, constitutes the One, True Thing, the Nicoise that casts its shadow on the wall?